The Old Testament raises some tricky questions of morality for people living in the contemporary world, at least in the west. The alleged 'genocide' of the Canaanites is one that I hear frequently. It isn't only people who are not Christians who have questions about it; Christians often feel embarrassed about these parts of the Old Testament. However, I am am convinced that there are some very good responses to these issues. I tried to outline a few responses in the first of a series of four sessions tackling difficult questions during Above Bar Church's Discipleship School in the autumn of 2014.
Paul Copan has, in particular, given a great deal of thought to this issue in his book Is God a Moral Monster? (I borrowed his title!). I learnt a great deal from him, not just from this book but from spending a little time with him at an apologetics conference in Sweden where we were both speaking. His more recent book, Did God Really Command Genocide? came out just after I gave this seminar, but I'm sure that will be even more thorough. I haven't had chance to read it yet. Chris Wright's The God I Don't Understand is also extremely helpful, and I found some useful insights in David Lamb's God Behaving Badly, which is, like Chris Wright's book, very accessible.
Here are the slides for this seminar. It wasn't recorded, unfortunately.