“These nations on the borders of Canaan would have been spared, had they not stood, in defiance of God's word, to oppose the progress of Israel. The Lord had shown Himself to be long-suffering, of great kindness and tender pity, even to these heathen peoples. When Abraham was shown in vision that his seed, the children of Israel, should be strangers in a strange land four hundred years, the Lord gave him the promise, ‘In the fourth generation they shall come hither again: for the iniquity of the Amorites is not yet full.’ Genesis 15:16. Although the Amorites were idolaters, whose life was justly forfeited by their great wickedness, God spared them four hundred years to give them unmistakable evidence that He was the only true God, the Maker of heaven and earth. All His wonders in bringing Israel from Egypt were known to them. Sufficient evidence was given; they might have known the truth, had they been willing to turn from their idolatry and licentiousness. But they rejected the light and clung to their idols.
“When the Lord brought His people a second time to the borders of Canaan, additional evidence of His power was granted to those heathen nations. They saw that God was with Israel in the victory gained over King Arad and the Canaanites, and in the miracle wrought to save those who were perishing from the sting of the serpents. Although the Israelites had been refused a passage through the land of Edom, thus being compelled to take the long and difficult route by the Red Sea, yet in all their journeyings and encampments, past the land of Edom, of Moab and Ammon, they had shown no hostility, and had done no injury to the people or their possessions. On reaching the border of the Amorites, Israel had asked permission only to travel directly through the country, promising to observe the same rules that had governed their intercourse with other nations. When the Amorite king refused this courteous solicitation, and defiantly gathered his hosts for battle, their cup of iniquity was full, and God would now exercise His power for their overthrow.” (White, Patriarchs and Prophets, 434, 435.)
The Fall of Jericho
“The inhabitants of Canaan had been granted ample opportunity for repentance. Forty years before, the opening of the Red Sea and the judgments upon Egypt had testified to the supreme power of the God of Israel. And now the overthrow of the kings of Midian, of Gilead and Bashan, had further shown that Jehovah was above all gods. The holiness of His character and His abhorrence of impurity had been evinced in the judgments visited upon Israel for their participation in the abominable rites of Baalpeor. All these events were known to the inhabitants of Jericho, and there were many who shared Rahab's conviction, though they refused to obey it, that Jehovah, the God of Israel, ‘is God in heaven above, and upon the earth beneath.’ Like the men before the Flood, the Canaanites lived only to blaspheme Heaven and defile the earth. And both love and justice demanded the prompt execution of these rebels against God and foes to man.” (White, 492.)