I'm listening to Richard Dawkins' The God Delusion right now, and he argues that morality is not rooted in the Bible. His reason is that the Bible has many things that strike people as immoral. He mentions Numbers 31, in which Moses gets mad at the Israelites for sparing the Midianite women in battle. Moses commands the Midianite women to be slain, while allowing the Israelites to spare the virgins for themselves.
Evangelical Christians have told me that God knows better than we do, so we should accept his word as authoritative, even when it appears to contradict our morality. What's ironic is that, in apologetics, many evangelicals actually try to reconcile the Bible's troublesome passages with our morality. Even in their eyes, our morality is still valid. Some may say "Shut up, morality! God can do what he wants," but many don't go that route.
Which takes precedence: the Bible or our morality? When the two are in conflict, is the Bible always right, especially in areas such as slavery or slaughtering men, women, and children? If our morality is cultural in any way, can it ever be wrong? The Bible strikes many people today as patriarchal, but maybe its focus on family has something to teach moderns, with their emphasis on individual autonomy. Or do the Bible and morality actually conflict? Maybe even the most troublesome passages of the Bible would seem moral to us, if we knew the full story.