he is heavy; he’s my brother

“The brother is a burden to the Christian, precisely because he is a Christian. For the pagan the other person never becomes a burden at all. He simply sidesteps every burden that others may impose upon him. The Christian, however, must bear the burden of a brother. He must suffer and endure the brother. It is only when he is a burden that another person is really a brother and not merely an object to be manipulated. … He who is bearing others knows that he himself is being borne, and only in this strength can he go on bearing.”

Life Together by Dietrich Bonhoeffer, translated from German by John W. Doberstein (Harper & Row, 1954), pp.100,103. First published in 1938 under the title Gemeinsames Leben.