In Matthew 19:8 Jesus told the Pharisees who questioned him about divorce that Moses allowed divorce because of their hard hearts. As a whole, ancient Israel simply wouldn’t accept a monogamous relationship. Therefore, in order to protect the more vulnerable woman, God (through Moses) commanded Israel how former wives and their children should be treated in the event a man should marry another woman. Even so, and remembering that it has been my position that Israel was at the time of his inheritance no more righteous than the Egyptians whom God had judged on Israel’s behalf, this idea of a hard heart should be explored in the light of the Canaanite wars.
The ancient ANE culture was a violent one. War was a way of life and often a means of survival (consider the ancient nomadic culture that didn’t farm but survived by raiding the settlements of other nations). How was a God of love able to reach out to this world and change it without taking away their right of free choice? What could influence such a violent world that had such an inconsiderate heart for their fellowman, and, remember, according to Matthew 19:8, Israel was no different than the nations who surrounded them, except perhaps in degree (since they were slaves for several centuries)?
Difficult choices are often involved in changing difficult circumstances. For example, in order for God to bless all nations through Abraham, Abraham had to be brought to the point of allowing God to be free to be God (Genesis 22:18). If God was to permit man to have free will, man must also allow God to be free to do his will, as well. Sometimes in doing this, man must surrender his own understanding of how his future should be played out. Nevertheless, obedience may bring about an enlightenment he had never before considered. Because Abraham was willing to sacrifice Isaac, he was able to conceive of a resurrection, something never even considered up to that time.
Numbers 14 tells an interesting story of God’s love. God makes out like he wants to destroy Israel and make a better nation out of Moses (Numbers 14:12). All the while, however, God is bringing something out of Moses that was difficult for him to express. Moses defended Israel and intervened on their behalf, asking that God forgive them, as he had always done up to that point (Numbers 14:17-19). Heretofore, Moses complained about Israel’s hardness of heart (Numbers 11:10-15). How did God soften Moses’ heart? He did it by causing him to deal with those difficult, hard hearted people—Israel. Moses’ own sin corrected him (cf. Jeremiah 2:19), because he had to face it every day. In the end, he decided to bear the problem of Israel’s hardheartedness, because he loved them.
Jonah recognized that Assyria was Israel’s fierce and powerful enemy. So, when God told him to go to preach repentance to Nineveh, Jonah immediately went as far away as he could get from the task at hand. He loved his nation and didn’t want to see it destroyed by the Assyrians. If God could be forced to judge Nineveh, perhaps Jonah could save his beloved nation. Nevertheless, he repented and went to Nineveh, allowing God to be God and knowing that God was gracious and compassionate to the point of loving his (and Israel’s) enemies (Jonah 4:2; Exodus 34:6). Nineveh repented and was saved (at least for a time) from God’s judgment, and Jonah left Israel’s fate in the hands of a gracious and compassionate God.
What does all this have to do with the Canaanites? Consider that God had issued an order to utterly destroy (H2763) the Canaanites (Deuteronomy 7:1-2). That is, they were devoted to destruction according to the Hebrew. No matter how one wishes to interpret the Hebrew—literally destroy every man, woman and child or destroy their national identity and drive the non-combatants out of the land—God ordered a complete destruction, like he implied for Israel in Numbers 14:12. What happened as a result of God’s order?
In the beginning Israel did exactly as they were commanded to do (Joshua 11:12-15). Remember, the ancient ANE culture was a violent one, and warfare was a way of life. Yet, in the midst of all this violence, Israel stopped its warfare and stopped driving out the Canaanites (Judges 1:21, 27-36). While it is true that life in the land would have been easier without their enemies living among them, Israel chose a troubled life to continued warfare (cf. Judges 2:1-7). It seems that God had worked on Israel’s hard heart (Matthew 19:8) by putting warfare before them constantly (cf. Moses’ position in Numbers 11:10-15 and 14:17-19 in the light of Jeremiah 2:19). In the end Israel would rather cope with a difficult life with the Canaanites, hoping to remain faithful to God, than an easier life without them. The Canaanites with all their moral problems were then absorbed into Israel, and Israel’s hard heart was softened toward violence—not completely, but certainly not like that of their neighbors. Progress was being made.
 As I said HERE, this current theme about “making sense of the Old Testament God” is based upon the book: Is God a Moral Monster by Paul Copan. These are my thoughts about his book. He may or may not agree with the impression his book has made upon me, but I thoroughly enjoyed reading what Paul wrote and recommend his book to anyone who is looking for a good read concerning defending our faith.