“Now when the unclean spirit goes out of a man, it passes through waterless places seeking rest, and does not find it. “Then it says, ‘I will return to my house from which I came’; and when it comes, it finds it unoccupied, swept, and put in order. “Then it goes and takes along with it seven other spirits more wicked than itself, and they go in and live there; and the last state of that man becomes worse than the first. That is the way it will also be with this evil generation.” (Mt 12:43–45; NASB)
I'm a keeper. I keep everything. When I work around the house, I buy extra of whatever I need so that I will have it the next time. When things break, I keep them because I might be able to use the parts from the broken one to fix something else (which I seldom do because I go buy a new one). I keep good things, and I keep junk. About once every six or seven years, I go on a cleaning spree. I straighten things up (never throw away), and I put everything in order. That is when I find I have all kinds of extra room for more junk, usually twice as much trash as I had before I straighten it up.
The same is true of Christians. When we cast out our old self, clean up our lives, and put everything in order if we don't fill it with something good; Bible study, church, small groups, etc., we will let it get cluttered up with twice as much "junk." That's why getting into the word of God is so essential, why fellowship with others is so important. We need to fill our lives with good so that there is no place for the bad / junk to fill up again.
So, fill your life with God and keep the evil things out.