The following writings of the early church fathers, came from the Wikipedia with its links intact.
Many of the Church Fathers taught that humans have the power of free will and the choice over good and evil. Justin Martyr said that 'every created being is so constituted as to be capable of vice and virtue. For he can do nothing praiseworthy, if he had not the power of turning either way'. 'Unless we suppose man has the power to choose the good and refuse the evil, no one can be accountable for any action whatever.' (The First Apology, 43). Tertullian also argued that no reward can be justly bestowed, no punishment can be justly inflicted, upon him who is good or bad by necessity, and not by his own choice. (Doctrine of the Will by Asa Mahan, p. 61). Likewise Origen , and Clement of Alexandria 
Justin Martyr said, “Let some suppose, from what has been said by us, that we say that whatever occurs happens by a fatal necessity, because it is foretold as known beforehand, this too we explain. We have learned from the prophets, and we hold it to be true, that punishments, chastisements, and good rewards, are rendered according to the merit of each man’s actions. Now, if this is not so, but all things happen by fate, then neither is anything at all in our own power. For if it is predetermined that this man will be good, and this other man will be evil, neither is the first one meritorious nor the latter man to be blamed. And again, unless the human race has the power of avoiding evil and choosing good by free choice, they are not accountable for their actions.” 
Justin Martyr said, “I have proven in what has been said that those who were foreknown to be unrighteous, whether men or angels, are not made wicked by God’s fault. Rather, each man is what he will appear to be through his own fault.” 
Tatian said, “We were not created to die. Rather, we die by our own fault. Our free will has destroyed us. We who were free have become slaves. We have been sold through sin. Nothing evil has been created by God. We ourselves have manifested wickedness. But we, who have manifested it, are able again to reject it.” 
Melito said, “There is, therefore, nothing to hinder you from changing your evil manner to life, because you are a free man.” 
Theophilus said, “If, on the other hand, he would turn to the things of death, disobeying God, he would himself be the cause of death to himself. For God made man free, and with power of himself.” 
Irenaeus said, “But man, being endowed with reason, and in this respect similar to God, having been made free in his will, and with power over himself, is himself his own cause that sometimes he becomes wheat, and sometimes chaff.” 
Irenaeus said, “Let your light so shine before men, that they may see your good deeds’…And ‘Why call me, Lord, Lord, and do not do the things that I say?’…All such passages demonstrate the independent will of man…For it is in man’s power to disobey God and to forfeit what is good.” 
Clement of Alexandria said, “We…have believed and are saved by voluntary choice.” 
Tertullian said, “I find, then, that man was constituted free by God. He was master of his own will and power…For a law would not be imposed upon one who did not have it in his power to render that obedience which is due to law. Nor again, would the penalty of death be threatened against sin, if a contempt of the law were impossible to man in the liberty of his will…Man is free, with a will either for obedience or resistance.