In his discussion with Evodius, Augustine sustains that evil does not originate with God, for God bestowed free will onto man, thus giving him the capability to choose between doing right and doing wrong. He first proves that man is incapable of "learning" to do evil. To learn evil is to be mislead, so in essence, we are not learning. We can only choose to go against what we have learned in order to sin. This makes God's punishment just because He punishes those who choose to sin and blesses those who choose to do His will. God is also not responsible for sin because of free will. Being that it is man that is choosing to sin, sin cannot originate with Him. Therefore, sin originates with man and suffering is God's punishment for it. .
If God knew that all this evil would come from free will, why would he make it? Doesn't this make Him responsible for the sin that man commits? This is the question posed by Evodius after Augustine established the notion of free will. Augustine answered, "An action would be neither sinful nor righteous unless it were done voluntarily. For the same reason both punishment and reward would be unjust, if man did not have free will." Therefore, man needs free will in order to act justly because without it everyone would behave the same. Life would be standard and there would be no difference between right and wrong. It is for this purpose that God bestowed free will onto man, so that man could use it to do his will and not to commit sins. .
One could be lead to think that Augustine's concept of free will renders man guilty of sin. But an interesting objection to this notion would be that one posed by Evodius where he stated, "I see that because it is uncertain whether free will was given that men might do right since by it we can also sin, another uncertainty arises, namely whether free will ought to have been given to us. If it is uncertain that it was given that we should act righteously, it is also uncertain that is ought to have been given at all.