Book 2 Opens

Book 2 Opens with Irenaeus categorically stating that this world was not created by a demiurge or by angels against the will of God, but by the one God through his Word. Much of his argument in the opening seven chapters is to seek to deconstruct his gnostic opponents by pushing their perspective to its logical extremities. One of his favourite arguments is that to suggest that creation is evil questions the goodness or the greatness of the One God,
" If again, as some say, their Father permitted these things without approving of them, then He gave the permission on account of some necessity, being either able to prevent [such procedure], or not able. But if indeed He could not [hinder it], then He is weak and powerless; while, if He could, He is a seducer, a hypocrite, and a slave of necessity, inasmuch as He does not consent [to such a course], and yet allows it as if He did consent."
Note however, how this is very close to the classical problem of evil and raises the question of how Irenaeus will account for the presence of evil in the universe created by the one great God.

On a different subject altogether, Irenaeus also claims that angels and demons have never seen God, but respect/fear Him due to His reputation.