They answered Joshua, and said, Because it was certainly told your servants, how that Yahweh your God commanded his servant Moses to give you all the land, and to destroy all the inhabitants of the land from before you; therefore we were sore afraid for our lives because of you, and have done this thing.
This action partially fulfilled Noah’s prophecy concerning the Canaanites in Genesis 9:25. The Gibeonites received tasks in the service of the tabernacle where, hopefully, they would have had exposure to the best spiritual influences. The Gibeonites never led the Israelites into idolatry, as far as the text records, but their presence in the tabernacle displeased the Lord (Ezekiel 44:7).