“No doubt, [God] adopted Abraham freely, but, at the same time, he stipulated with him that he should live a holy and an upright life, and this is the general rule of the covenant which God has, from the beginning, made with his Church. The sum is, that hypocrites, who occupy a place in the temple of God, in vain pretend to be his people, for he acknowledges none as such but those who follow after justice and uprightness during the whole course of their life.”

John Calvin, Commentary upon the Book of Psalms, Psalm 15.