Dietrich Bonhoeffer:

If we do not give thanks daily for the Christian fellowship in which we have been placed, even where there is no great experience, no discoverable riches, but much weakness, small faith, and difficulty; if on the contrary, we only keep complaining to God that everything is so paltry and petty, so far from what we expected, then we hinder God from letting our fellowship grow according to the measure and riches which are there for us all in Jesus Christ.

This applies in a special way to the complaints often heard from pastors and zealous members about their congregations. A pastor should never complain about his congregation, certainly never to other people, but also not to God. A congregation has not been entrusted to him in order that he should become its accuser before God and men.

. . . let [the pastor or zealous member] nevertheless guard against ever becoming an accuser of the congregation before God. Let him rather accuse himself for his unbelief. Let him pray God for an understanding of his own failure and his particular sin, and pray that he may not wrong his brethren. Let him, in the consciousness of his own guilt, make intercession for his brethren. Let him do what he is committed to do, and thank God.