What is compassionate when a brother is sinning?

“Reproof is unavoidable. God’s Word demands it when a brother falls into open sin. The practice of discipline in the congregation begins in the smallest circles. Where defection from God’s Word in doctrine or life imperils the family fellowship and with it the whole congregation, the word of admonition and rebuke must be ventured. Nothing can be more cruel than the tenderness that consigns another to his sin. Nothing can be more compassionate than the severe rebuke that calls a brother back from the path of sin. It is a ministry of mercy, an ultimate offer of genuine fellowship, when we allow nothing but God’s Word to stand between us, judging and succoring. Then it is not we who are judging; God alone judges, and God’s judgment is helpful and healing.  Just because God’s Word judges, it serves the person. He who accepts the ministry of God’s judgment is helped.”

― Dietrich Bonhoeffer, Life Together: The Classic Exploration of Faith in Community