Mark S.M. Scott, on this monograph on Origen’s theodicy, wrote the following:
Why does God endow human beings with freedom, especially in light of the disastrous results that God presumably foreknew? Origen offers two explanations. First, God did not want to create automata, creatures preprogrammed to worship and enjoy God. Rather, God desired that all creatures would choose to embrace and appropriate the goodness that God originally bestowed to creation: “For the Creator granted to the minds created by him the power of free and voluntary movement, in order that the good that was in them might become their own, since it was preserved by their own free will.” (On First Principles 2.9.2) Second, God wanted to create creatures the good. In answer to the question whether God can transform sinners into saints via divine fiat, Origen argues at the development of virtue of the integrity of free will. Without freedom, true virtue cannot be cultivated:
Was it impossible for God by divine power even to make men needing correction good and perfect there and then so that evil should not exist at all? These arguments may carry away the uneducated and unintelligent folk, but certainly not the man who analyzes the nature of the problem. For if you take away the element of free will from virtue, you also destroy its essence. (Contra Celsum 4.3)
Hence, God gives freedom to creatures so that they may freely internalize the goodness that God imparts to them by taking responsibility for their own actions and choices. (Mark S.M. Scott, Journey Back to God: Origen on the Problem of Evil [Oxford: Oxford University Press, 2015], 68-69)
