If God is full of mercy, why does He seem so merciless in the Old Testament? For example, let’s look at Joshua 11:14–15: “And all the spoil of these cities and the livestock, the children of Israel took as booty for themselves; but they struck every man with the edge of the sword until they had destroyed them, and they left none breathing. As the Lord had commanded Moses his servant, so Moses commanded Joshua, and so Joshua did. He left nothing undone of all that the Lord had commanded Moses.” Why would a God of love authorize and encourage such violence?
Know that all passages of the Bible must be studied in context. When we do that, we see that nothing contradicts God’s loving and merciful character, even the Old Testament.
The Canaanites mentioned in the passage from Joshua were an anti-God society, wicked in every way imaginable, and proud of wickedness. In Leviticus 18, we read that the appalling list of their gross sins included child sacrifice, incest, adultery, homosexuality, and even attempting to mate with animals. On two occasions recorded in Joshua 9:1 and 11:1–5, they even tried to annihilate God’s people.
God is a promise keeper. He had promised Abraham that anyone who cursed Israel would then be cursed themselves: “I will bless those who bless you, and I will curse him who curses you; and in you all the families of the earth shall be blessed” (Genesis 12:3). The Canaanites provoked God Himself and hence invited their own judgment. Their own sin beckoned God’s wrath.
Know, also, that the Israelites were not given permission to kill anyone they pleased. The specific instructions were to destroy a people whose sin could no longer be tolerated by God. Since the Canaanites’ goal was to destroy Israel, God was saving His own people. Once again, He is a promise keeper, which sometimes results in harsh judgment for some and kindness for others.
Joshua 11:14–15 in no way contradicts the Biblical truth that God is a loving and merciful God. It supports a God who says what He means and means what He says. In keeping with His promises, He will forgive those who seek His pardon but punish those who refuse it and persist in their wicked way.