"Ye shall drive out all the inhabitants of the land. But if ye will not drive out the inhabitants of the land from before you; then it shall come to pass, that those which ye let remain of them shall be pricks in your eyes, and thorns in your sides, and shall vex you in the land wherein ye dwell." --- Numbers 33:52, 55.
See this fulfilled, Judges 1:27. --- "Neither did Manasseh drive out the inhabitants of Bethshean, etc., and the Canaanites would dwell in that land; so that they (the Israelites) could no longer stand before their enemies." --- Chapter 2:14.
The very same is to be observed in the holy and spiritual battles of the Lord. He that fights only against outward sins, but very little, if at all acquainted with the dangerous enemies in his heart, or the deep corruption of original sin; and so, the tempter may easily gain an advantage over him. Experienced Christians guard more against the inward assaults of wickedness; they are at peace with no sin, but keep up a constant war with all their most subtle and darling lusts.
However, though the Canaanites, our inbred foes, must be conquered, they will dwell in the land, and cannot be wholly thrust out of the bosom, which makes the Christian warfare continue till death. Yet give me grace, O Lord, never to spare my sinful lusts and tempers, but to look to destroy them without delay, as soon as they begin to move or stir that I may not be destroyed by them.
O Prince of Peace, forgive my guilt,
Though more than I can tell;
And from the pow'r of sin release,
And from the hosts of hell.
Furnish me, Lord, with heavenly arms,
From grace's magazine;
And I'll proclaim eternal war
With every darling sin.