On the Unchangeableness of God (73-75)

But God, remembering his own perfect goodness in every particular, even if the whole or the greater part of mankind fall off from him by reason of the abundance and extravagance of their sins, stretching forth his right hand, his hand of salvation, supports man and raises him up, not permitting the whole race to be utterly destroyed and to perish everlastingly.

On which account God now says, that Noah found grace in his sight, when all the rest of mankind appearing ungrateful were about to receive punishment, in order that he might mingle saving mercy with judgment against sinners.

For if God were to choose to judge the race of mankind without mercy, he would pass on them a sentence of condemnation; since there has never been a single man who, by his own unassisted power, has run the whole course of his life, from the beginning to the end, without stumbling; but since some men have fallen into voluntary, and some into involuntary sins,