Men are possessed with free will, and endowed with the faculty of making a choice. It is not true, therefore, that some are by nature good, and others bad. (Against Heresies, Book IV, Chapter XXXVII)
Man is endowed with the faculty of distinguishing good and evil; so that, without compulsion, he has the power, by his own will and choice, to perform God’s commandments. (Against Heresies, Book IV, Chapter XXXIX)
Those who do not do it [good] will receive the just judgment of God, because they had not worked good when they had it in their power to do so. But if some had been made by nature bad, and others good, these latter would not be deserving of praise for being good, for they were created that way, nor would the former be reprehensible, for that is how they were made. However, all men are of the same nature. They are all able to hold fast and to do what is good. On the other hand, they have the power to cast good from them and not to do it. (Against Heresies (Book IV, Chapter 37)
This expression, ‘How often would I have gathered thy children together, and thou wouldst not,’ set forth the ancient law of human liberty, because God made man a free (agent) from the beginning, possessing his own soul to obey the behests of God voluntarily, and not by compulsion of God. For there is no coercion with God, but a good will (toward us) is present with Him continually. And therefore does He give good counsel to all. And in man as well as in angels, He has placed the power of choice (for angels are rational beings), so that those who had yielded obedience might justly possess what is good, given indeed by God, but preserved by themselves… (c. 180, Against Heresies 37; God’s Strategy In Human History, p. 246)
And to as many as continue in their love towards God, does He grant communion with Him. But communion with God is life and light, and the enjoyment of all the benefits which He has in store. But on as many as, according to their own choice, depart from God. He inflicts that separation from Himself which they have chosen of their own accord. But separation from God is death, and separation from light is darkness; and separation from God consists in the loss of all the benefits which He has in store. Those, therefore, who cast away by apostasy these forementioned things, being in fact destitute of all good, do experience every kind of punishment. God, however, does not punish them immediately of Himself, but that punishment falls upon them because they are destitute of all that is good. (Against Heresies, Book V, XXVII, 2)