In his classic book, The Holiness of God, R.C. Sproul deals with this issue in some detail. OT Jehovah gets criticized by some for His presumed harshness in dealing with the Canaanites for example. (1) “Far from being a history of a harsh God, the Old Testament is the record of a God who is patient to the extreme.” He heard the Israelite slaves in Egypt cry for help. He rescued them via Moses and the Red Sea miracle. “They responded by worshiping a gold cow.”
(2) “Sin is cosmic treason.” None of us is innocent before a holy God. It’s an act of mercy that any us is allowed to live past midnight tonight. Never cry for justice. Mercy is our only hope. (3) God has given us so much patience and grace and mercy that we take it for granted. Now we demand it but God owes us nothing. “We delude ourselves into thinking that either God doesn’t care about it or that He is powerless to punish us.” (4) The Canaanites and certain other pagan groups were also idol worshipers. some even offered child sacrifices. ” There was none innocent. The conquest of Canaan was an explicit expression of God’s righteous judgment on a wicked nation.” (5) “The most violent expression of God’s wrath and justice is seen in the cross. If ever a person had room to complain of injustice it was Jesus. He was the only innocent man ever to be punished by God. Here is where our astonishment should be focused . . . Golgotha.” (6) We cringe when justice is administered while taking His grace and patience for granted. It is we who are out of step—unthankful for God’s mercy.