I rather thought this god we are talking about was one of the 3 omni kind -all knowing, all-powerful, and all-present. Now if that's the case,
1. He would have know before he created anything what would happen if he created in a particular way
2. he would have know what would happen when he told Adam about the tree of knowledge of good and evil (Heck, if this tree was so significant, why plant it within reach of the people? )
3. By the time he has killed everyone with a flood (as he knew he would have to), surely he would have known how to re-populate the earth so as to make sure he didn't need to deploy Jesus.
These are important questions and ones that there ought to be good answers for. Frankly, if we resort to things like, 'we don't know' not only are we giving up on knowledge but we are also opening the door wide to the question, 'why should this god be worshipped or even believed in when he couldn't create that well?'
Of course, as usual, this has already been thought of by the Greeks....
Epicurus [341–270 B.C.] Greek philosopher:
Is God willing to prevent evil, but not able? Then he is not omnipotent.
Is he able, but not willing? Then he is malevolent.
Is he both able and willing? Then whence cometh evil?
Is he neither able nor willing? Then why call him God?