In Philippians 3:13-14, the Apostle Paul whom we all know as one of the greatest missionaries, preachers, and witnesses for Christ who ever lived, wrote the following: "Brethren, I count not myself to have apprehended: but this one thing I do, forgetting those things which are behind, and reaching forth unto those things which are before, I press toward the mark for the prize of the high calling of God in Christ Jesus."
If you know the history of Paul before he gloriously met the Lord Jesus on the road to Damascus, then you know he was a man better known by his Hebrew name of Saul. Saul of Tarsus was filled with bitter hatred toward Christians. He had taken it upon himself to single-handedly drive the Christians out of existence, whether it meant beating them, imprisoning them, or even taking their life.
Paul's past would come back to haunt him over and over as he strove to work in the ministry of the Lord. There were many people who could not forget his once evil ways and would always doubt his conversion and sincerity. In fact, even Jesus' own disciples didn't believe he was truly saved because in Acts 9:26 the Bible says: "And when Saul was come to Jerusalem, he assayed to join himself to the disciples: but they were all afraid of him, and believed not that he was a disciple."
But, praise the Lord there were some who did not hold Paul's past against him, such as a man named Barnabas. Acts 9:27 says: "But Barnabas took him, and brought him to the apostles, and declared unto them how he had seen the Lord in the way, and that he had spoken to him, and how he had preached boldly at Damascus in the name of Jesus."
Despite the fact that not everyone accepted Paul and would always hold his past against him, the most important thing was that he found forgiveness for himself and did not let his past define him. He boldly declared; "but this one thing I do, forgetting those things which are behind, and reaching forth unto those things which are before, I press toward the mark for the prize of the high calling of God in Christ Jesus." Does that mean that he somehow blanked all of his past out of his mind never to remembered again? Absolutely not! What he means is that despite his past, despite what others may say or think, he is not going to allow that to define who he is today. He will not allow his past to hinder his relationship or his calling to share the Gospel.
Now, what about you friend? Are you living in the past and allowing it to define you? When you stand before others that you once mistreated or acted foolishly or sinfully in front of, do you allow those past actions to keep you from being a witness? Everyone has a past and things in their past that they deeply regret. We cannot go back and change these things or make it as if they never happened but we do not have to allow them to define us. There will always be those who are too petty and arrogant to forgive you, we must pray for them and realize that they haven't yet grasped the true teachings of Christ. Why don't you put your past behind you and reach unto those things which are before? Don't let your past define you!