One soldier was completely out of step and as he passed his mother, she remarked "Look, the only one in step is my son!" Soldiers are all taught to step in time with one another. Nobody is supposed to be out of step. But in life, we are all different. No two fingerprints, no iris color and shape, and no ear is identical to anyone else's. Every cell in our body differs from that of others. We also think differently due to the many experiences in life we have all had.  

Each person steps to the music that he hears, and in the family of God there will be no "identical twins" born. The word of God is our music, but we may have slight differences in the way we follow. Paul realized that we ought not to judge or condemn others since we hardly know them. It is God who is our judge and He tells us that He is able to make a person stand (Romans 14:4-5). Marching to God's music takes time and practice.  Let your neighbor learn at his own speed. God says he is not out of step just because your step and his differ.