The “self” of two individuals may have its own unique problems that become difficulties among others. Only the Christ within can resolve the “self” first, and then the problem between one another.
God permits such divisions to brothers as part of the sifting and shaking of the church in the End Time. This is one of the ways God brings out of us that which needs to be dealt with by grace.
When we are born again we enter the family of God. We are now brothers and sisters. We must do all we come to maintain our relationship in the unity of the Spirit in the bond of peace.