To understand what was happening when the people of Israel stormed the cities of Canaan and slaughtered their inhabitants, we need to go back about 500 years. In Genesis 15:13, 16 God says to Abraham, “Your descendants will be strangers in a land that is not theirs, where they will be enslaved and oppressed four hundred years…. Then in the fourth generation they shall return here, for the iniquity of the Amorites is not yet complete.”
The return of Israel to the Promised Land from Egypt would correspond with the “completion” of the iniquity of the Amorites. This is the meaning of the slaughter of the peoples of Canaan. God timed the arrival of his judgment with the fullness of the sin to be judged. Not before. God did not jump the gun. He was, in fact, longsuffering and endured the idolatry and sins of the nations for centuries, giving them “rains from heaven and fruitful seasons, satisfying [their] hearts with food and gladness” (Acts 14:17). As Derek Kidner says, “Until it was right to invade, God’s people must wait, if it cost them centuries of hardship. [Genesis 15:16] is one of the pivotal sayings of the Old Testament” (Genesis, p. 125).
But there comes a time when the sins of a people are “complete.” That is the time for decisive judgment. The appointed instrument of God’s judgment was the army of Israel. But God sees himself as the effective warrior behind the defeat of the Amorites. He says to Joshua, “I brought you into the land of the Amorites…and they fought with you; and I gave them into your hand, and you took possession of their land when I destroyed them before you” (Joshua 24:8). God did the destroying. It was by the hand of Israel, but it was the judgment of God. This does not mean that Israel’s motive was always holy. At times it was not. But the just purposes of God were being carried out, even if Israel at times had wrong motives.
In fact, God warned the people against pitiless pride in Deuteronomy 9:4-5: “Do not say in your heart when the Lord your God has driven them out before you, ‘Because of my righteousness the Lord has brought me to possess this land,’ but it is because of the wickedness of these nations that the Lord is dispossessing them before you…in order to confirm the oath which the Lord swore to your fathers, to Abraham, Isaac and Jacob.” In other words, this carnage is not about human injustice, but divine judgment. The Amorites provoked God to anger for centuries by their idolatry—so much so that centuries later the wicked king Ahab was compared to the Amorites: “He acted very abominably in following idols, according to all that the Amorites had done, whom the Lord cast out before the sons of Israel” (1 Kings 21:26).
One implication of this for us is that, as the church of Jesus Christ, we may not imitate Israel. The church is not God’s instrument of judgment in the world; it is his instrument of evangelization and reformation. We have no ethnic or geographic or political identity. We are “aliens and exiles.” God’s dealing with Israel was unique in redemptive history. He chose them and ruled them as a demonstration of his holiness and justice and electing grace among the nations. But to the church he says, “My kingdom is not of this world; if it were, my servants would fight” (John 18:36).