The first principle for maintaining unity when Christians disagree (accept one another - Romans 14:1-12) has to do with our remembering that we are not the master of other Christians and that they are not our servants but the Lord’s servants. God is the head of the family and those whom He has accepted are His children. Since we are children in the family and not the head of the family we don’t try and tell the others what our Father’s will for them is in the gray areas. We accept those whom God has accepted because they are our brothers and sisters in Christ.
The second principle for maintaining unity when Christians disagree (build up one another - Romans 14:13-23) has to do with our remembering that we are brothers and sisters with other Christians. Not only do we accept one another, we build up one another. Here we discover five responsibilities to build up one another in the family.
First, don’t cause your brother to stumble (Romans 14:13). Instead of judging each other, Christians are to determine (judge) this – not to put an obstacle or stumbling block in a brother’s way.
Second, don’t hurt your brother (Romans 14:14-15). The apostle Paul was a strong Christian. He knew his liberties in Christ. He knew that he could enjoy anything the Lord hadn’t declared sinful. But he also knew that there were weak Christians who thought certain things were unclean and not permissible although the Lord had not declared it so. So the strong Christian is completely right in his conviction that he is at liberty to enjoy anything the Lord does not declare to be sinful. The weak Christian, on the other hand, is wrong in his understanding about some of those things. But he is not wrong in the sense of being heretical or immoral. He is wrong in the sense of not having complete and mature understanding of the Word of God in these areas, which causes him to believe that something is sinful when it isn’t really.
However, if he believes something to be sinful and then is enticed by a strong believer to partake in it, he violates his conscience and his submission to the Lordship of Christ, he stumbles and is hurt (see 1 Corinthians 8:7-13). The strong Christian, then, is no longer walking according to love. This is harmful and not helpful. It will seriously impair the spiritual growth of the weaker Christian (15b).
Third, don’t forfeit your witness (Romans 14:16-18). A strong Christian can lose his witness if he uses his liberties in a manner that puts an obstacle or stumbling block not only in a brother’s way but also in the way of men outside of the faith.
Fourth, don’t tear down the work of God (Romans 14:19-21). A strong Christian can also misuse his liberties to the point that his good thing can become an evil thing because he gives offense through it.
Fifth, don’t flaunt your liberties (Romans 14:22-23). The strong Christian who knows his liberties must be so concerned for his weaker brothers and his own witness that he keeps his conviction between him and God. The strong Christian then is to exercise his liberties in private. He is not to force his opinions on anyone else. That goes for the weak Christian also. The reason is that whatever is not from faith is sin. I can’t give another Christian permission to do something he thinks is wrong. His permission must come from his understanding of God’s Word because his obedience must be to the Lord and not me.