Jebu-PSYCH!

You that annoying word, "psych" that people use when they tell you they were fooling you? Example:
Me: Hey Jeff, can you pass me that glass of water?
Jeff: Sure. [extends said glass of water]
Me: Thanks [reaches out]
Jeff: Psych! [pulls back the glass of water and drink it himself]
Yeah, it's annoying. Usually when someone tells you something, you want to be able to believe them. When the children of Israel were set free from Egypt, God made them a promise:

But if you indeed obey His voice and do all that I speak, then I will be an enemy to your enemies and an adversary to your adversaries. For My Angel will go before you and bring you in to the Amorites and the Hittites and the Perizzites and the Canaanites and the Hivites and the Jebusites; and I will cut them off. You shall not bow down to their gods, nor serve them, nor do according to their works; but you shall utterly overthrow them and completely break down their sacred pillars.
Exodus 23:22-24

In essence, God promised the children of Israel complete victory in the Promised Land. They will UTTERLY DESTROY their enemies. Seems kinda harsh, doesn't it? Well, in Deut. chapter 7 God tells them why. First of all, He's using the Israelites to judge these nations for their wickedness. He also tells them the danger of letting them live:

“When the LORD your God brings you into the land which you go to possess, and has cast out many nations before you, the Hittites and the Girgashites and the Amorites and the Canaanites and the Perizzites and the Hivites and the Jebusites, seven nations greater and mightier than you, and when the LORD your God delivers them over to you, you shall conquer them and utterly destroy them. You shall make no covenant with them nor show mercy to them. Nor shall you make marriages with them. You shall not give your daughter to their son, nor take their daughter for your son. For they will turn your sons away from following Me, to serve other gods;
Deuteronomy 7:1-4

Ok, there seems to be some explanation. The Lord delivers them to us, we conquer them, leave nothing. Most of all, definitely not fall in love and marry them. Okay. Got it.

A few chapters later:

As for the Jebusites, the inhabitants of Jerusalem, the children of Judah could not drive them out; but the Jebusites dwell with the children of Judah at Jerusalem to this day. Josh. 15:63

What?! Did God just PSYCH the Israelites? Did He not deliver them into their hands? What went wrong?? I'm thinking that it wasn't God's side that was let down, but the Israelites. They did not press on and drive them out. It's not that the Lord did not deliver the nations up to the Israelites, it's that the Israelites didn't obey the Lord and eradicate them. In fact, those nations must have had pretty good looking daughters. What the Lord warned against happened: they intermarried and ended up serving dead idols instead of the One True God.

Thus the children of Israel dwelt among the Canaanites, the Hittites, the Amorites, the Perizzites, the Hivites, and the Jebusites. And they took their daughters to be their wives, and gave their daughters to their sons; and they served their gods.
Judges 3:5-6

This was a bad, bad, bad idea. Something small, like leaving a few nations in the land (you gotta have servants, after all...) became a very tangled web. They did not convert the nations, the nations converted them to serve their gods. How many times do we let something small stay in our lives? Some impatience with someone, some pride, a little frustration, an unconfessed sin. How soon does that balloon into a massive wall that completely prevents our fellowship with God?

The Jebusites (one of the nations) continued to be a problem, even until David's time. They inhabited Jerusalem and taunted David and said that even the weakest of their people could defeat David and his army. Talk about a thorn in the side. Did David pass by? Did he let that situation smolder? No, "he took the stronghold of Zion."

And the king and his men went to Jerusalem against the Jebusites, the inhabitants of the land, who spoke to David, saying, “You shall not come in here; but the blind and the lame will repel you,” thinking, “David cannot come in here.” Nevertheless David took the stronghold of Zion (that is, the City of David).
2 Sam. 5:6-7

We, like David, must confront those sins that try to get ahold on us. They weave their tentacles so slowly and tenderly we hardly feel it until it chokes us to death. Instead, we need to be pulling down those strongholds, and thanks be to God that we are equipped for battle. The Word of God is our battle weapon. Don't let it get rusty!