I've been addicted to porn for about six years and recently gave it up, after many fails. A verse in the Bible is really worrying me about my salvation: "But I say, anyone who even looks at a woman with lust has already committed adultery with her in his heart" (Mathew 5:28). Sometimes random words like "sex" will just pop into my head, like in big black bold lettering, along with pornographic images (seems like they're on a big screen laying on the inside of my forehead, that's the best I can explain it). Will this be forgiven if it continues? And how do I get these thoughts out of my head? It's really troubling. I know God forgives all sins, so every night should I confess and ask for forgiveness for my thoughts?
First, congratulations on giving up pornography. That alone is a difficult thing to do. I'm glad to hear that you have had success.
We need to make a distinction between temptation and lust. "But each one is tempted when he is drawn away by his own desires and enticed. Then, when desire has conceived, it gives birth to sin; and sin, when it is full-grown, brings forth death" (James 1:14-15). James says the steps to spiritual death are:
- A desire for something
- A temptation, which is an offer to gain what is desired with the trap that you have to break a law of God to get it.
- Lust, which is an acceptance that breaking God's law is worth getting what you desire.
- Sin, which is the actual breaking of God's law.
- Licentiousness, which is sin full-grown. That is when a person gets to the point that he doesn't care what anyone thinks about his sins, he is going to do it anyway. He thinks he has a license to sin.
- Death. When a person stops caring there is no way to bring him back.
You can't stop desires because they are built into you. You can't stop yourself from getting hungry, thirsty, wanting sex, wanting to be liked, etc. These are all normal, healthy desires. Satan takes those desires and twists them so that it looks like you have to sin in order to get what you want. Thus, you are hungry, realize you have no money, and it becomes tempting to steal a candy bar. Since temptations originate with Satan, you can't stop the temptations either -- you can only reject what Satan offers. "Therefore submit to God. Resist the devil and he will flee from you" (James 4:7). But when you start justifying stealing, such as telling yourself you'll pay the guy back later or that you are owed a candy bar, even though it wasn't offered, then you are committing the sin of lust. This is something you can work against because it is originating with your decisions. If you take the candy bar, then it becomes the sin of stealing. When you've stole things so often that it no longer bothers you and you don't give it a second thought, then you've moved into licentiousness. And there you have died spiritually.
Since you passed puberty you've discovered you have sexual desires. Satan is trying hard to get you to sin with those desires. He's offering pornography and sensual situations to fan the flames of your desires -- knowing that a guy who is sexually aroused doesn't think well. He'll offer you sex when you are not married knowing full well that it would be hard for you to resist. Satan doesn't care how you sin, just as long as he can trap you in sin. And he doesn't fight fair.
Your body wants sex, even if it is not experienced with sex. It isn't picky about who or what causes you to orgasm, just as long as you do. Thus, everything and anything looks attractive. This is where your mind is supposed to come into play. You teach your body what is right and wrong by limiting its responses. Just as you tell yourself that you'll wait for dinner even though you are hungry right now, you need to tell yourself that sex belongs in marriage and you'll wait until you are married even though you want sex right now. "Marriage is honorable among all, and the bed undefiled; but fornicators and adulterers God will judge" (Hebrews 13:4).
What you are experiencing is temptation. Yes, it would be nice to go back to the innocent days when you didn't realize what sex was, but the clock can't be reversed. Nor can the memories be fully erased from when you sinned and chased after the lusts of pornography. However, you've moved in the right direction. You stopped the input of tempting images. Over time those images will fade. The second step is to replace these things with righteous concepts. Start getting to know girls as people and not as sex objects. It will be difficult at first, but over time and with effort it will get easier.
You haven't sinned because you have been tempted. But you can easily stray into lust if you start dwelling on those sexual thoughts and start telling yourself that looking "one more time" won't hurt. It is when you catch yourself straying into lust that you need to pray both for help and for forgiveness.