Brotherhood means oneness. God and everything created by Him put together is Brotherhood. You do not need to say, “I want to be Brotherhood”. Everyone is Brotherhood. Brotherhood has no origin. It has no beginning and it has no end, except such a person wants to know the origin of God. God is Love. Brotherhood therefore means the unity of all creatures of God bounded by love. Who owns Brotherhood? It is God who owns it, rules and leads it. But Christ takes charge.
The disobedience of Adam in the Garden of Eden caused the division in the history of Brotherhood. The fact that we had scattered because of the disobedience of Adam does not mean that we are no more in Brotherhood. God is still reigning over His people. The shedding of the Blood of Christ means the making of peace for all the scattered brethren. This peace clears the way for all to come together again in the same fold in Brotherhood.