When we got saved Jesus became the substitute for the punishment we deserved. He took our place and when we accepted Jesus' offer of Salvation, Jesus traded us for Him. In the Bible, Paul expresses it as "clothing us in Christ." Clearly stated, what it says is "I empty myself to Jesus and I receive all of Him in me." It’s a trade; all of me for all of you. Except, we do not give all ourselves because we did not know we were expected to or even know how. Thus, begins our walk with Christ and as we actively walk with Him, He reveals the areas in our lives that are not right. The goal here is to empty ourselves of us and fill up on Jesus. If we do not fill up on Jesus, that is when the trouble begins.
24 “When an unclean spirit goes out of a man, he goes through dry places, seeking rest; and finding none, he says, ‘I will return to my house from which I came.’ 25 And when he comes, he finds it swept and put in order. 26 Then he goes and takes with him seven other spirits more wicked than himself, and they enter and dwell there; and the last state of that man is worse than the first.”
Also reference Matthew 12:43-45.
As God breaks strongholds in our lives there is a natural void left which must be filled to prevent Luke 11 from occurring. It is somewhat reasonable to assume that if God sets you free, you are already protected. If you are newly saved, the Holy Spirit covers you like a parent covers or protects their child. As you grow in the Lord, you are expected to read and learn the Word. Bottom line here is as my experience reflects, you can get free and then get re-infected, however I have never seen anyone seven times worse. Although getting free a second time is much harder, so there is truth to additional resistance.
31 And when they had prayed, the place where they were assembled together was shaken; and they were all filled with the Holy Spirit, and they spoke the word of God with boldness.
17 that Christ may dwell in your hearts through faith; that you, being rooted and grounded in love, 18 may be able to comprehend with all the saints what is the width and length and depth and height— 19 to know the love of Christ which passes knowledge; that you may be filled with all the fullness of God.
29 I will not drive them out from before you in one year, lest the land become desolate and the beasts of the field become too numerous for you. 30 Little by little I will drive them out from before you, until you have increased, and you inherit the land. 31 And I will set your bounds from the Red Sea to the sea, Philistia, and from the desert to the River. For I will deliver the inhabitants of the land into your hand, and you shall drive them out before you. 32 You shall make no covenant with them, nor with their gods. 33 They shall not dwell in your land, lest they make you sin against Me. For if you serve their gods, it will surely be a snare to you.”
This is one of my favorite scriptures. It explained to me what I was going through and why it was taking so long. We must grow in the Lord for these walls to fall or we will be overrun with trouble. In order to do so, I need to let my will be overwritten by the Will of God. My goal is to empty myself of me and fill it up with Jesus (His Word and Holy Spirit). To be abundantly clear, all of me for all of Jesus then the glory of God will shine through you continually. Like medicine every day, we need to take in some Jesus and we will be well and make others well.