The story of the Akedah, the Binding of Isaac (Gen. 22), begins, “After these things, God tested Abraham”, i.e. God sought to ascertain whether Abraham really believed in Him and could be trusted with a Divine mission.
A necessary test? How could it be, when God already knows everything?
Many of the classical commentators explain that it was not God Himself, but Abraham, who needed to find out the extent of his obedience when asked to do something so difficult that other people would have refused.
Maimonides (Guide to the Perplexed 3:24) says that the important thing is not just Abraham’s obedience but his motivation. In other circumstances a person – even Abraham – might obey out of fear of punishment; but here there was no other possibility than sheer love of God.
Maimonides also speaks about God’s motivation. Implicit in the words of the Divine angel, “Now I know…” (Gen.22:12) is the idea that until the Akedah God did not really know how Abraham would respond.
It sounds quite inconceivable that God should lack knowledge of anything. Says Maimonides, it all depends on what you mean by “knowledge”.
“To know” has more than one meaning, and God’s knowledge is not the same as ours. We and our knowledge are distinct: here am I, here is my knowledge. God and His knowledge, indeed God and all His attributes, are one and the same.
The words “Now I know” do not imply that hitherto God did not know but “now My knowledge is confirmed”.
Rashi suggests that God is saying, “Now I can give a reason for My love for Abraham”.