Article VIII: What the Church Is
Although the Church properly is the congregation of saints and true believers, nevertheless, since in this life many hypocrites and evil persons are mingled therewith, it is lawful to use Sacraments administered by evil men, according to the saying of Christ: The Scribes and the Pharisees sit in Moses’ seat, etc. Matt. 23, 2. Both the Sacraments and Word are effectual by reason of the institution and commandment of Christ, notwithstanding they be administered by evil men.
They condemn the Donatists, and such like, who denied it to be lawful to use the ministry of evil men in the Church, and who thought the ministry of evil men to be unprofitable and of none effect.