Years before my girlfriend, who is my wife right now, and I had committed fornication and I got her an abortion. I was so sorry, even now, and regretful I allowed this things to happen, but it happened. Prior to our planned marriage, I converted and become a Christian. I repented of my sins and knew I was forgiven.
Then it all began when weeks before our marriage I had sex with her even though I knew it was a sin. I justified it in my mind thinking she will become my wife anyway, with all the public preparations, etc., and so I thought it should be OK. I was really a hypocrite to claim to be a member of the church that Jesus bought, and I was so wicked being involved in fornication! I've asked God to forgive me of this, but it seems they keep resurfacing in my mind. I still felt guilty about it. And especially the abortion. I just can't get them off my mind. Why do I still not feel forgiven? Is forgiveness all about feelings?
Then, being led to many temptations I lapsed back into my old problem of pornography and, you know what's next, masturbation. I struggled to stop it, on and off, and now have managed to stopped it, yet I still feel not forgiven. Why is this? I really began to doubt my faith because of these sins. I love the Lord, please help me what I needed to do to get back to the Lord. Now I still don't know how to start again with my spiritual life. My wife doesn't know about how I struggled spiritually as she's not a Christian yet because I did not have courage to tell her. And obviously, I was really a stumbling block to her knowing Christ in her life. I would really appreciate your biblical advice. Thank you.
I'll do my best to answer your questions, though this is one of those times I think it would be better if we were sitting down at a table together to cover your issues.
No, forgiveness is not about feelings. Feelings come and go. They change from moment to moment. Forgiveness is a gift offered to us by God. "In Him we have redemption through His blood, the forgiveness of sins, according to the riches of His grace" (Ephesians 1:7). It is never about our deserving to be forgiven, but rather our trust in God that He is willing to forgive even though we realize that we don't deserve it. That is why we speak of the mercy of God. Mercy giving someone less that what justice demands that they deserve to receive.
Do you deserve to be forgiven because you committed fornication, encouraged the killing of your own child, and have lusted after other women through pornography? No. But then neither do I deserve forgiveness for the sins that I've committed. Yet I trust God and know that He has chosen to forgive me because I was willing to obey Him. "If we say that we have no sin, we deceive ourselves, and the truth is not in us. If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness" (I John 1:8-9). Thus I can fall to my knees in thankfulness that the Lord has given me a gift beyond what I deserve. Look at how Paul, who once had Christian's murdered, felt about his forgiveness: "And I thank Christ Jesus our Lord who has enabled me, because He counted me faithful, putting me into the ministry, although I was formerly a blasphemer, a persecutor, and an insolent man; but I obtained mercy because I did it ignorantly in unbelief. And the grace of our Lord was exceedingly abundant, with faith and love which are in Christ Jesus. This is a faithful saying and worthy of all acceptance, that Christ Jesus came into the world to save sinners, of whom I am chief" (I Timothy 1:12-15).
But going back to I John 1:9 and notice that when God offers us forgiveness, it is because He is both faithful and just. God isn't breaking the rules because He has offered you salvation. It was the just and proper thing to do. ""But if a wicked man turns from all his sins which he has committed, keeps all My statutes, and does what is lawful and right, he shall surely live; he shall not die. None of the transgressions which he has committed shall be remembered against him; because of the righteousness which he has done, he shall live. Do I have any pleasure at all that the wicked should die?" says the Lord GOD, "and not that he should turn from his ways and live?"" (Ezekiel 18:21-23). God's way is perfectly fair because He has declared that He judges us based on who we are and not who we were, and it is equally applied to both the righteous and the wicked.
But the key point is that God is faithful in offering forgiveness to you and everyone else who comes to His throne. He is trustworthy. He always keeps His word because He cannot lie (Titus 1:2; Hebrews 6:17-18). When you say you don't "feel" forgiven you are both saying that you have not forgiven yourself and that you don't believe God meant what He said. So is it any wonder that your doubts have undermined your faith in God in other areas as well?
If you haven't told your wife, then one day you ought to tell her that you are sorry about both the fornication and abortion. Tell her that over the years you have grown and realized what a poor Christian you were back then.
In regards to the pornography, if you haven't already, trash it. If you are getting to it through the Internet, put blocks or filters on your computer. Pornography, like other addictive sins, is best conquered by first giving yourself space where it isn't an issue for a while. The lack of input will give you a chance to reorganize your thinking and make it easier to reject in the future. But this is something that would not be appropriate to discuss with your wife unless she brings it up. For you to bring up the subject would cause your wife to doubt herself and the love in the marriage. This has to be a burden that you bear alone.