Adam Clarke on 2 Kings 17:33

They feared the Lord, and served their own gods - They did not relinquish their own idolatry but incorporated the worship of the true God with that of their idols. They were afraid of Jehovah, who had sent lions among them; and therefore they offered him a sort of worship that he might not thus afflict them: but they served other gods, devoted themselves affectionately to them, because their worship was such as gratified their grossest passions, and most sinful propensities.