Irenaeus saw the pre-Fall Adam as more like a child than a responsible adult. Adam was at the beginning of a long process of development. His fall was not as disastrously transforming man’s situation, but rather as delaying his advance from the “image” to the “likeness” of his Creator known as God. Ireneus less dramatic conception of the Fall has been carried further by Hick. The Fall is regarded as an inevitable incident in man’s development as a child of God. Only a relatively independent being can enter a relationship of love and trust with his Maker (God), and man’s fall is a fall into this independence. It is analogous to the disobedience which signals a child’s assertion of his own individuality in relation to his parents.
Irenaeus insisted that the fullness of salvation, is only to be found by maintaining communion in Church, outside the church there is no salvation. Here Hick's theodicy begins to differ more from Irenaean theodicy. While Hick's have follow Irenaean theodicy in its broad outlines, his view required universalism. Hick posits an eschatological universalism in which every human person will eventually achieve full consciousness of God and thus salvation or liberation. If anyone were to be denied the salvation, creation is unjustified. Since people are usually not very developed at the end of this life, they go on to become reincarnated in other worlds many times until they are perfected enough to get off the wheel of life. There is no hell, at least no permanent hell. The process of soul making, which requires obstacles for its completion, must then continue in another realm, until the soul is perfected and brought into intimacy with God. Unless everyone will eventually enter a limitlessly good end-state the problem of evil cannot be solved. Hick thus holds that there can be no successful theodicy apart from eschatology.
Main references
John Hick - Evil and the God of Love 1966
John Hick - Death and Eternal Life 1976
John Hick - Theodicy 1967 Encyclopedia of Philosophy