reading from God's holy and inerrant word, Acts 1, verses 1 through 11. In my former book, Theophilus, I wrote about all that Jesus began to do and to teach until the day he was taken up to heaven, after giving instructions through the Holy Spirit to the apostles he had chosen. And after his suffering, he showed himself to these men and gave many convincing proofs that he was alive. He appeared to them over a period of 40 days and spoke about the kingdom of God. On one occasion, while he was eating with them, he gave them this command, Do not leave Jerusalem, but wait for the gift my father promised, which you have heard me speak about. For John baptized with water, but in a few days you will be baptized with the Holy Spirit. And so they met together. They asked him, Lord, are you at this time going to restore the kingdom to Israel? And he said to them, it's not for you to know the times or the dates the Father has set by his own authority, but you will receive power when the Holy Spirit comes on you, and you will be my witnesses in Jerusalem, in all Judea and Samaria, and to the ends of the earth. And after he said this, he was taken up before their very eyes, and a cloud hid him from their sight. And they were intently looking up into the sky as he was going, when suddenly two men dressed in white stood beside them. Men of Galilee, they said, why do you stand here looking into the sky? This same Jesus, who has been taken from you into heaven, will come back in the same way you have seen him go into heaven. This is God's word. Father, we thank you for your word, for your truth, for your grace. And we ask now that your spirit might enlighten us in its truth, that we might further understand your will and serve you in this world through Jesus Christ and for his sake, amen. Each summer, some of us go to the shore for family vacations. I wonder if any of you have been to the shore this summer. Myrtle Beach, Jersey Shore. For my family, it was the Connecticut shoreline, where at low tide, sandbars would appear, almost like a string of tiny islands. And you could walk out into the bay a long time. but be careful because the tide comes in fast. And it often, not often, but it had happened that people would be stuck out there because they didn't heed the warning and come back to the shore, especially dangerous if you couldn't swim. And so people were rescued because they went out too far at low tide. The disciples were in low tide. in the upper room and people needed to be rescued. They were in low tide because Jesus said to them in the upper room, one of you will betray me. They were shocked. Who could it be? And then he also said in John 16 in the upper room, because I have told you these things that I'm going to leave you, Your hearts are full of grief and sorrow. Low tide for the apostles. But the all-time record low tide for the apostles followed the crucifixion. Remember? They scattered. They went everywhere. They thought it was all over with. What have we been doing these last years? He's gone now. Even though he told them at least three different times what was gonna happen. I imagine some of their conversations were, well, let's go home now, it's all over with. But where's their faith? Three years of hearing Jesus Christ speak, teach, perform miracles, where is their faith? Where especially is their assurance? The majority of Christians today think that they cannot have assurance, assurance of their faith, assurance of knowing for certain that they're going to heaven, because by grace through faith they've been joined at Jesus Christ. By assurance, I mean knowing that you are in a state of grace. And you know that your entire life now is a mission trip every day for Jesus Christ. And at the very end of that mission trip, you're going to come before him. You're going to come before his throne. Assurance of salvation is possible and desirable. But the Westminster Confession of Faith says it's not of the essence of faith, Dr. Gerstner, one of my professors, said this, undoubtedly there are Christians who went to heaven being insecure all the way But the Apostle Peter teaches us this, that our duty as Christian people is to make certain your calling and your election in Jesus Christ. Assurance of faith comes with the Spirit of God bearing witness with our spirit that we belong to him, that we've been adopted into his forever family. And the assurance grows when the Spirit of God takes the Word of God and makes it shine in us, takes the truths of God, the gospel of God, the promises of God, and makes those things shine in us. John 5, John writes, these things I have written to you that you may know that you have eternal life. And now our passage this morning is the first 40 days between the crucifixion and the ascension, between Easter and the ascension. full of assurance for building the church, for building our lives and our families. And the way I'd like to divide this passage is verses one through five, the assurance of convincing truths, and then six to eight, the assurance for our mission as witnesses for Jesus Christ. And then finally, the assurance that comes when Jesus Christ ascended to sit at the right hand of the Father, where all authority in heaven and earth has been given to him. Verses one and two, Luke writes, in my former book, I wrote about all that Jesus began to do and teach until the day that he was taken up into heaven, after giving instructions through the Holy Spirit to those apostles that he had chosen. Luke ends the gospel that he wrote and begins the narrative of Acts with the Ascension. The Ascension is kind of a bridge between those two great works that God inspired. For 40 days, Christ, risen from the dead, was building assurance in his apostles, teaching them, counseling them, encouraging them, instructing them through the Spirit. We get a little idea what that must have been like when in Luke 24, Jesus has ridden, and Cleopas and another disciple were walking home on the road to Emmaus. Remember that passage? You have to say yes to encourage me once in a while. Okay? So they were walking, and the Risen Lord comes behind them, and And in that passage, Luke says he opened their minds so that they could understand the scriptures. That's just a little taste of what Jesus did in those 40 days of building assurance into those apostles, preparing them for the ministry of the church of Jesus Christ. He taught them how to preach faith and repentance and forgiveness of sins to all sorts of people, using the Psalms, using the law, using the historical books. And so here is the reliability of Scripture. Here is the reliability of Scripture in verses one and two. Luke is such a careful historian. He uses eyewitness accounts. He interviewed all of the people. He carefully investigated everything he wrote. And of course, he was inspired by the Holy Spirit. He was a traveling companion of the Apostle Paul. That's why he could write such detail in the book of Acts. You see, the point is this. Our faith is a historical faith. Take away history, and Christianity disappears. The Ascension, the 40 days, it's not Mythology. It's not a legend. It's not a metaphor. It's history. Luke says, on the day that he went up to heaven. You see, a day. Verse 3, After his suffering, he showed himself to these men and gave many convincing proofs that he was alive. And he appeared to them over a period of 40 days and spoke about the kingdom of God. I'm reading from the NIV, by the way. Many convincing proofs that he, indeed, risen from the dead. The apostles knew that he had died. Many of them saw the nails driven into his hands. Some of them stood there at the cross that horrible day when the sky turned black. They saw the spear thrust into his side. If Christianity was just a philosophy or the resurrection is just a legend, they never would have come back because they knew that he had died. But the reliability of many convincing proofs in verse 3, proofs of the resurrection, brings assurance to them and to us as well. He appeared to Peter. He appeared to doubting Thomas. Remember what Thomas' reply was in the upper room? When Jesus says, here, Thomas, come and stick your fingers in these wounds, remember what he said? He said, my Lord and my God, that's for us also. The resurrection is true. The ascension is true. My Lord and my God, it's all true. In my senior year at Duquesne University, I think right after the Civil War, I needed to take a religious elective. I was a new Christian then, I was a young life leader, I was a regular at the study center when RC had the study center in Stallstown, not actually Ligonier, Stallstown. And so my choices were either a course on Saint Teresa, or a course on the seven sacraments of the church, or a course on modern Protestant thought. Well, I thought, hey, I'm going to go with modern Protestant thought here. The professor taught a very popular book at the time, written by Rudolf Bultmann, who was a liberal, a progressive. He was all about demythologizing the Bible, demythologizing the resurrection of Jesus Christ. Imagine. The way that Rudolf Biltnam explained the resurrection, it was all a myth. It was all made up. It didn't really happen. Or at best, it was a metaphor, right? And so, after the professor would present his lecture, there was always time for discussion. There was maybe 15 in there. None of the other students said anything, but I was incensed. What do you mean? The resurrection is a mythology. What do you mean, professor? Because if he didn't rise, you know what I'm gonna say, then our faith is in vain. We're the biggest fools in the world. Well, I'm sure I overdid it. I'm sure I came across as a pinheaded conservative, but I couldn't keep it inside. This was just too much. If Jesus Christ never rose, we're still in our sins. The resurrection and the ascension proves that he is God, that he is deity. And Jesus said, do not leave Jerusalem, but wait for the gift that my father has promised. And what is that gift that the father has promised? The baptism of the Holy Spirit. the baptism of the Holy Spirit. Look at verse four. Do not leave Jerusalem, but wait for the gift which you have heard me speak about. John baptized with water, but in a few days you will be baptized with the Holy Spirit. He's talking about Pentecost there. When the baptism of the Holy Spirit fell, It fell not just upon the apostles, but upon all of those believers that were present that day. On every believer. And the promise of Pentecost and the gift of the Holy Spirit and the power that the Holy Spirit is gonna give to us, the assurance that he gives, brings us to verses six to eight. So when they met together, The disciple said, Lord, are you at this time going to restore the kingdom to Israel? And he said, it's not for you to know the times or the dates the Father has set, but you will receive power when the Holy Spirit comes upon you and you will be my witnesses. Here's the mission of the church and the assurance of the Holy Spirit to empower the church, to empower you. to empower the apostles for this mission that he's given to us. But notice the apostles, first comes a question. Now, after three years of hearing Jesus Christ teach about the kingdom of God, teach about his mission, after three years, of on-the-job training, 40 days of resurrection appearances, 40 days of this assurance that he gives to them, they ask, are you gonna restore the kingdom to Israel at this time? In other words, are you gonna make Israel great again? Is that what this is all about? And you would think Jesus would say, what knuckleheads you are. You're asking me that question after all this time, after all that I've taught you? But no, Jesus Christ, what a wonderful Savior we have and covenant-keeping Lord that He is. Jesus says, no. Regarding the kingdom, none of what you ask, am I going to do? I'm not come to make Israel great again. Instead, go and wait for the Spirit of God and you will receive power. The Greek word is dynamis, like dynamite. And when the Holy Spirit comes upon you, you will be my witnesses. He did answer their question, actually, because it takes power to build a kingdom. It takes power to tell others about Jesus Christ. They were expecting a political kingdom immediately. But no, the kingdom of God is the rule of God in the lives of his people by the Holy Spirit. The kingdom of God is invisible until Christians and until his church makes it visible by living Coram Deo before his face. His kingdom is spread by witnesses, not by soldiers. It's spread by the gospel of grace, not by weapons of war. And so Jesus told them and us, he says, your job is to be my witnesses. And if you're not, then you're not obeying me. The ascension is all about, you're my witnesses, now get busy. I've given you something to do, and I've given you the Holy Spirit to empower you to do it. Verse eight. and you will be my witnesses in all kinds of places, even to the ends of the earth." The emphasis in verse 8 is on two things. The power the Holy Spirit brings to us to accomplish this, because we don't have the power in ourselves, 1 Thessalonians 1.5, our gospel comes to you not only in word but in power and in the Holy Spirit with full conviction. Here is assurance for us. The Holy Spirit is the real evangelist. He's the real evangelist. He comes and effectually calls people through our message, through the preaching of the word, through the witness of his people. and through that effectual witness, convicting people of sin and of their need for a savior, enabling them to embrace Jesus Christ, who's freely offered to all. And the second thing is this, the worldwide expansion of Christianity. You know, think of this. Here are the last recorded words of Jesus Christ before the ascension, and what does he say? You are my witnesses. What happens when we excuse ourselves from being his witness? What happens when we leave it up to somebody else to tell our neighbors and other people in our family about the Lord Jesus Christ? What happens to the church? The church becomes a museum. A museum. Dr. James Kennedy told us one time, that there was a tour in one of those huge cathedrals in London, and the tour was going on, and the lady that was leading the tour group was saying things like this, well, this wing over here is designed by this famous architect, and over here is our famous pipe organ with 300 ranks of pipes and four manuals. And over here is our 40-member choir portion, all paid, by the way. And in the floor are buried some of the ministers that used to be here. And then in the midst of that tour, somebody from the tour that was being guided spoke up, an older lady, and she said, Excuse me, but are there people being saved around here? When the fire goes out, and a church stops witnessing, the church becomes a museum. I've been to Sweden. That's what many of the churches there are. They're just museums. And you pay a little bit of money, and they give you a tour of what used to happen there. God forbid. God forbid. Exalted above the heavens, Hebrew says, is Jesus Christ who lives to make intercession for his people. He takes our prayers because he's the ascended Lord who sits in session at the right hand of the Father. He takes our prayers and it makes them beautiful, brings them to the Father. Dr. Gerstner gave us this little illustration one time about what one of the things that the Ascension has accomplished on our behalf. The story goes like this. A little boy in the ancient world loved his father very much and he wanted to present him with a gift because his father had been on a long trip and away from home for quite a while. And so his mother sent this little boy to the garden to gather a bouquet together. And he gathered a bouquet of weeds and a few flowers But when his father returned, he received only a bouquet of beautiful flowers because the mother picked out all the weeds and put all the flowers together in a beautiful arrangement. The prayers of God's people are always acceptable, but they're not always full of beauty. Because as our prayers start out heavenward, they're mixed with weeds and maybe a few flowers. But when they arrive through the intercession of Jesus Christ to the Father, all the weeds are gone and Christ makes them beautiful. And then in verse nine, finally, this defining moment when Jesus Christ was taken up for us. After this, Luke writes, he was taken up before their very eyes, and a cloud hid them from their sight. This is history. This is an eyewitness account. What a beautiful picture. In Luke 24, Jesus Christ lifted up his hands in blessing, and then it was as though this glory cloud lifted him up to heaven, and the apostles watched him go. They looked intently. Wouldn't you? Wouldn't you watch him intently rise until you could no longer see him anymore? Of course you would. How could you not resist doing that? And then the angels say, why are you looking up? I think that's kind of an unfair question, actually. Here's the assurance. Here's the assurance. He is seated at the right hand of the Father, far above all rule of authority in this world. And now every authority must answer to Him. And in His reign, He's working all things together for good. to those who love and have been called according to his purpose. Here's all this assurance for us, Calvin Presbyterian Church. All this assurance for us, assurance for our mission, assurance for our witness. Ascension means to get busy. There's work to be done. The ascension means your labor is not in vain, because right now counts forever. The ascension means get busy obeying Jesus Christ in your life. Those things that right now you're determining what you're gonna do, you're tempted not to obey Jesus Christ, obey him. He's risen, he's ascended. One day, your mission trip is gonna end before his throne. Obey him. right now counts forever. All authority in heaven and earth has been given to us. Let me pray. Father, thank you for your Word this day. We pray that as a result of hearing your Word, Lord, that we would be growing in assurance and confidence in Encourage us, Lord, because of the truth of the ascension, to witness for you and not to be afraid, to obey you, Lord. Do those things, Lord, that we need to do to honor you. We pray in Jesus' name and for his sake and all of God's people said, amen.