I wasn't asked about the conquest of Canaan during Thursday's debate. But if I was, here are 5 minutes worth of thoughts prepared in advance. (Quite a bit was taken from Paul Copan's Is God a Moral Monster?)
There’s not a Christian in the world who doesn’t read Scriptures like Deuteronomy 20:16-18 without a lump in their throat. But this jarring sensation does not come in spite of their Christianity, but precisely because of it. Christians don’t need to step outside the bible to learn the infinite and intrinsic value of human life. We don’t need humanist ethicists to tell us how to treat our enemies. Jesus Himself has taught us:
“Love your enemies, pray for those who persecute you, bless those who curse you, bless and do not curse them, turn the other cheek, go the extra mile, if your adversary sues you for your coat, give him the shirt off your back, don’t pick up the sword, those who live by the sword will die by the sword, my kingdom is not from this world otherwise my followers would fight for me but my kingdom is not from this world, the kingdom of heaven is within, etc, etc.”
Atheists haven’t taught Christians to be sensitive to the spilling of blood, Jesus has. And, never forget, Jesus has taught both believers and unbelievers of the West exactly the sensibilities that make these ancient stories so difficult to our ears. We look back at these three and a half thousand year old stories and find it almost impossible to think ourselves into their war-like worlds. A massive reason for that is the advent of Christianity.
Nonetheless, the Christian is faced with Jesus who tells us both to put down our own swords and to take up His book - the Old Testament. Jesus emphatically tells us that these Hebrew Scriptures are His Scriptures. We cannot have Him and not His book. So how then do we read it?
Well as we go back to the OT, what we see are Canaanite cultures involved in child-burning levels of evil. For four hundred years they are engaged in repugnant spiritual and moral wickedness. And, having given them four hundred years to repent of it - considerably longer than any other "just war" ever launched! - God visits them with a one off, unrepeatable judgement.
And it has nothing to do with ethnicity. This is not genocide, there is nothing racial about this. It’s about spiritual and moral evil which, when the Israelites are guilty of it, they too are conquered by foreign nations. What we see is a God who gives the Canaanites 400 years to repent. Every Canaanite who ever sought mercy from the Israelites was granted mercy. It's true that, prior to the conquest, there is language of total destruction and “giving over” whole cities to the LORD, actually the language of “driving out” the Canaanites precedes and predominates over language of “wiping out.” Copan argues that this is militaristic hyperbole that, even within the Bible, is fulfilled in non-literal ways. i.e. the Canaanites just weren't wiped out (nor were the Korahites). The narrative of the wars does not describe non-combatants being killed (Copan argues that Jericho and Ai were fortresses - military installations if you like). And when Joshua sums up his achievements he considers that he's done what Moses had commanded - this, in spite of the Canaanites not even being wholly driven out, let alone "wiped out."
Now there is still a bloody intensity in these stories that confronts our placid, peace-time sensibilities. And there is a fearfulness to the judgement of God falling here in history. But if we tell God he should do more about the evil of this world and then He gives us a one-off, unrepeatable pre-figurement of His righteous judgement – we can’t then complain at His intervention! God can bring judgement. God does bring judgement. God will bring judgement.
If you read the OT you realise God is not a Rotarian. He’s not an old softy. There is blood and fire and justice to the Living God. But when you read the NT you get the same. Jesus is not Sweet. But neither does He allow us to take justice into our own hands. Jesus absorbs the fire and the justice on the cross. He sheds His own blood for His enemies and as He does so He prays “Father forgive them.” The Kingdom He brings is one of cheek-turning, enemy-forgiving, love. There is blood-shed in Christ's kingdom - but it's our own blood shed in place of our enemies. There can be no Christian genocide. That is a contradiction in terms.
On the other hand, what is it about atheism that absolutely rules out mass murder? What if it really achieved a greater goal for the species? What if it would preserve more favoured races in the struggle for survival? Is it at all possible that a mass murderer could justify their actions as consistent with a thorough-going atheism? They wouldn't win humanist of the year, that's for sure. Certainly, no atheist I know wants to do such things, nor do they want to provide any justification for it. But can such evils be perpetrated consistently within atheism? I contend that the answer is yes. Therefore the problem of genocide does not lie in millennia old Hebrew wars. It lies in the here and now. And the answer is not to jettison Jesus or His book. Instead we need to return again to the Crucified PeaceMaker.