Epicurus and God
If we had no freewill given to us by God, even the good things we do would not be considered good at all, for outside freewill we are nothing more than robots and we therefore would not know the difference of right or wrong.

Without freewill there would be neither good nor evil. Therefore allowing freewill allows both evil and good to exist. With this in mind, (God is in no way, directly or indirectly, the cause of moral evil.) Simply because God respects the freedom of His creation (man and woman) and, through the power of examples and influences of what is right; God knows how to derive good from people’s hearts.” In other words, God proves Himself to be all powerful because He rules the world through the power of persuasion only and not by force.

If God took the world by force to cause our actions to be all good, freedom would be taken away and therefore we would be controlled. Evil therefore is the abuse of freedom God gave us.
It is true that without self-interest there is no freedom, and because of self-interest we would rely only on instincts and impulses and we would be mentally incapable of
choice, reason, and motive.

Therefore, the existence of choice is dependent on freewill. Knowing that God is all-powerful and neither desires to control us and do away with self-interests proves that we are completely responsible for our own actions and will be judged by them by God on judgement day.

What God will not do for humanity is take away self-responsibilities because that would mean an unbeliever in God can escape from their choice in God without judgement? Hence, if God takes away evil by force, than things such as lies or stealing something as a pencil would be done away with, and therefore each person would become a robot.

This being said, every behavior is motivated by a belief, and where you will find unbelief and rejection of God in the world you can find that it is translated into evil actions. In other words, anyone who does not obey God by His word will commit evil. With this in mind, can evil be avoided; the answer is (yes). How? By staying right with God and following His commands. Therefore, God desires to prevent evil, God wishes to prevent evil just as much as He desires and wishes each person to come to salvation in Christ but will not force people to do so.  

God's promise to the world 
 2 Chron 7:14 "My people who are called by My name will humble themselves, and pray and seek My face, and turn from their wicked ways, then I will hear from heaven, and will forgive their sin and heal their land."
Epicurus contradiction about God is clear on wisdom, morality, and justice can only be derived by our own freewill.