God is too 'nice' to judge sin would be to underestimate HIM... Deu7

God told Isrealites to completely destroy their enemies. How can a God of love and mercy wipe out everyone, even children?

Although God is loving and merciful, HE is also just. These enemy nations were as much a part of God's creation as Israel was, and God doesnt allow evil to continue unchecked. God had punished Israel by keeping out of the Promised Land all those who had disobey.

The command to destroy these nations was both a judgment and a safety measure. On one hand, the people living in the land were being judged for their sin, and Israel was God's instrument of judgment--just as God would one day use other nations to judge Israel for its sin. On the other hand, God's command was designed to protect the nation of Israel from being ruined by the idolatry and immorality of its enemies.