Numbers 33:55 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.
Every thing written in the Old Testament is there to teach us a lesson or give us an example. Here God told His children to drive out the enemies from their land, to destroy them. The enemies represent sin.
He warned them that if they let their enemies, sin, live in the land that it would be like a stick in the eye, a thorn in the side, and a constant aggravation.
Too many Christians live right there. We want victory. It is ours if we would but get it but we often do not get it. We keep living with our sin. We suffer. We are aggravated. It is a constant nagging pain but we refuse to just kick it out completely!
Some one has convinced us that the sin is worth the aggravation! Do you really want to live like that?