Because, although they learned to know God, yet they did not offer him as God either praise or thanksgiving. Their speculations about him proved futile, and their undiscerning minds were darkened.
There was, you remember, a time when we ourselves were foolish, disobedient, misled, slaves to all kinds of passions and vices, living in a spirit of malice and envy, detested ourselves and hating one another.
Let your daily life among the Gentiles be so upright, that, whenever they malign you as evil-doers, they may learn, as they watch, from the uprightness of your conduct, to praise God 'at the time when he shall visit them.'
These men, however, like animals without reason, intended by nature to be caught and killed--these men, I say, malign those of whom they know nothing, and will assuredly perish through their own corruption,
But these men malign whatever they do not understand; while they use such things as they know by instinct (like the animals that have no reason) for their own corruption.