Augustine based his theory on his reading of key biblical passages

Augustine suggested that there was a state of blissful ignorance in the Garden of Eden, which was then knocked of balance by the Fall. Biologists have formulated that the theory of natural selection, in which the innate selfishness of creatures became a virtue in the battle for survival. However if God can be held responsible for the system by which the natural world works, he should be held responsible for the suffering that his system causes. A more complicated problem is associated with the idea of collective responsibility. Why should people suffer for the misfeasors of past generations. Even the Bible argues this in Jeremiah. Augustine makes much of the idea of hell - as part of creation, God must be responsible for its creation, so he must have foreseen the need or punishment.

The theodicy of Irenaeus believes that humans were created in the image and likeness of God. We are in an immature moral state, though we have the potential for moral perfection. Throughout our lives we change from being human animals to "children" of God" This is a choice made after struggle and experience as we choose God rather tan our baser instincts. There are no angels or external forces at work here. God brings in suffering for he benefit of humanity. From it we learn positive values and about the world around us. Suffering is a necessary part of God's created universe - it is through suffering that human souls are made noble, the world is a "vale of soul making"

The Irenean theodicy is soul making and is more concerned with the development of humanity. One o the ways in which this "test" is carried out is through faith - God's purpose cannot easily be discerned, but believers continue to believe despite the evidence. This faith becomes a virtue. John Hicks calls this lack of understanding as "epistemic distance". Suffering and evil are useful as a means of knowledge, character building and for a predictable environment.

Irenaeus argued that everyone goes to heaven. This would appear unjust in that evil goes unpunished. Morality becomes pointless. It has been argued that it is not possible that suffering can be justified on the grounds of motive, suffering does not sit easily with the concept of loving God. The Irenean Theodicy allows room for the concept of evolution and avoids some of the problem associated with Augustine, especially the notion that evil seem to have come from no where. The challenges of the world do not always result in a genuine human development, and often seem to produced nothing but suffering a misery. Such as the Holocaust, there is no need for such extreme forms of suffering and evil.

http://www.philipallan.co.uk/images/388-T2.pdf