You are in a battle in a spiritual war. You must understand the nature of the battle and the war.

 God created you as spirit, mind/soul/heart, and body, just as the Bible says.  If you are born again (by trusting Jesus) you have been changed in your spirit and, to some extent, your mind/soul/heart. However, you no doubt still have much of your mind that is in it's natural, sinful condition. The natural mind cannot do any righteousness. It cannot be reformed. It is the old Adam along with your body. If you are born again, you also have a measure of the mind of Christ. Part of your mind has been transfigured into His likeness. This is the battleground. Each battle is for the mind.  The war is for the spirit, mind, and body, but the current battle is for the mind.

It is easy to go off the tracks into speculation in these issues. God has revealed some things to us, but not everything. God hasn't told us how everything works, but He has told us that we are spirit, soul/mind/life/heart, and body/flesh. There is an innermost mind that is referred to as the kardia, the conscience, or the reins. We do know this: the present battle is focused mostly on the mind. The Holy Spirit is influencing us from the one side and the fallen spirits are working through the Satan's slaves and our own flesh/body to influence us from the other side. Once someone is born again, they still have a largely flesh-controlled (fleshly) mind, but they also have a measure of the mind of Christ. Obedience to Christ progressively kills the flesh and builds up the Christ in us. Obedience to Satan progressively re-crucifies the Christ in us and brings us into more severe slavery to Satan. The mind is where the battle rages. Who will we yield ourselves as slaves to obey, whether the flesh, which leads to progressive death (separation from God) or whether the Holy Spirit, which leads to the genuine and absolute fullness of Life (Jesus Christ)?

The body has a heart, but so does the mind. Scripture speaks of this heart of the mind. Out of the heart proceed evil thoughts, murders, adulteries, and such like. Guard your heart, for out of it are the issues of life. The love of God is shed abroad in our hearts by the Holy Ghost. As the blood is the life of the body, so there is life that streams from the heart of the mind. But we must guard our heart from the onslaught of ungodliness from ungodly sources, the world, the memories of past sins of our own and of others, and the influence of demonic forces. The best way to guard the heart is to direct it toward Christ who protects us.

Satan gets at us through our bodies and the fleshly part of our minds, our natural minds. The Holy Spirit works with us through our spirits and through our new minds. Our new minds are, in reality, Christ in us. Our transformed Spirits have been transfigured into His image and likeness as well. Christ is the spiritual man. He cannot sin. (1 Jn. 3:4-11) Our old fallen nature cannot do anything but sin. It can be a hypocrite and try to look righteous, but it will only be able to do the dead works that are self-generated. There is no mixing of the Christ in us and our fleshly nature. Our fleshly nature tries to re-crucify the Christ in us. When we obey the leading of God, our fleshly nature is crucified within us--not all at once but a little bit. And we also live to Christ when we obey the leading of the Holy Spirit. Christ is more fully formed in you each time you obey the Holy Spirit. This is how the battle is fought: you have a will that you can turn toward God or toward your sinful flesh. Satan can't make you sin and God won't force you to do righteousness. You have a will.

 Now, here is how righteousness works. At any moment, both your fleshly nature and the Holy Spirit are speaking to you. They are telling what to think, say, and do. Your fleshly nature will always lie and make sin seem glorious or fun or cool and make righteousness seem trite, silly, old fashioned, boring, and even wrong. When you ignore the voice of your own fleshly mind and listen to Christ, He speaks a vision of hope into your mind/heart/soul. The apostle, James, compared this vision of hope as you looking into a mirror. In 1 Corinthians 13, the same analogy to a mirror is used and again in 2 Corinthians 3, which says, "as we all, with unveiled faces, looking as if looking into a mirror, are transfigured into the same image from glory to glory by the Spirit of the Lord." This is the vision of hope. When God speaks to you, you see who you are destined to be in Christ, how you fit into the body of Christ, what is the body of Christ, and what is not the body of Christ. You don't see it clearly yet, but as you walk into Him, it will become more and more clear (only if you obey, though).

(some caveats about hearing God's Voice)

 Along with hope, when God speaks, faith comes. Faith cometh by hearing and hearing by the word (literally, utterance) of God. Faith is supernatural trust in God. It is actually the faith of God that is a gift to you--"lest any man should boast." The Bible tells us that faith is what gives you access to God's grace and that it is grace that does the works of God through you. This is the love of God that is shed abroad in your heart by the Holy Ghost.

 I can tell you from experience that sin corrupts the mind/heart/soul. It plants bitter seeds that spring up at times and trouble you. You reap what you sow. However, when God does His work through you, when you yield to the Holy Spirit, many of those old evil seeds are killed and new living seeds of holiness are planted. You are changed in your very nature. When you are in an anointed church service, you are changed in your very nature. And God has set authority in His Church to overcome these things. You can pray. The members of your church can pray. If you know a true shepherd of God, he can pray for you for complete deliverance. I was struggling with something for years. I had committed sin that had left me as a slave to Satan in certain areas of my life. I went to my own elder in the Church and confessed my problem and asked him to pray for me. He laid his hands on my shoulders and prayed. Authority is transferred by the laying on of hands. Immediately, I was set free. God has delivered me and is continuing to deliver me, and He is willing and able to deliver you, too.