Mt. 5:223,24 "Therefore if you bring your gift before the altar, and there remember that your brother has something against you, leave your gift there before the altar, and go your way. First be reconciled to your brother, and then come and offer your gift."
Growing up with a brother two years younger than myself I discovered that I could play the part of the bully anytime I wanted to play with something that he was playing with. I'm sure he would agree that I got away with that kind of behavior frequently.
But sometimes I got caught. And when I got caught there were consequences. Usually a "switching" or a few lashes with Dad's belt. This was their way of keeping peace in the family. And over time it worked. By the time I had entered the teenage years I recognized that if my relationship with my brother wasn't good, then my relationship with my father would not be good either.
Jesus makes it clear to all who desire to worship God the Father that our relationship with our church brethren must be good. If it isn't then there will be a major consequence; God won't accept our worship!
Just as there will be relationship issues in any earthly family, there will, from time to time be relationship issues between members of the family of God. When we ignore our wrongs against our brethren there are two huge risks we run. First we risk causing the brother we have hurt to stumble or fall. But even if he doesn't fall God will still hold us accountable for making things right. His punishment is that He won't receive our worship.
So how would you like to have to explain to God someday why you refused to apologize to another member of the body of Christ? The easy answer is that we wouldn't like that task. But yet, hear what Paul tells us in 2 Cor. 5:10, "For we must all appear before the judgment seat of Christ, that each one may receive the things done in the body, according to what he has done, whether good or bad." I think this knowledge really puts everything in proper perspective. Don't you? Think about it.