I have been having this battle with doubting my salvation for four years now.  Most of the time when I talk to someone about it their first conclusion is that I am not really saved.  So I find myself going through the sinners prayer over and over. I know I am a sinner and want to be saved more than anything in the world. I have repented of my sin and asked Jesus to be my savior. The thought that keeps making me doubt is how do I know if I really trusted Him?  Did I really accept him and if I didn’t how can I ever?  Every time I hear a preacher say do you know you are saved beyond a shadow of a doubt I feel somewhat angry because I fear I will never know.  Some nights I can’t sleep because I fear those words “depart from me ye who work iniquity I never knew you”.  I just keep thinking what if God says that to me because I really never accepted.  It’s like I am afraid to believe I am saved because what if I really am not.  Then I am afraid to believe I am not because I have done everything I can to be saved and fear if I am not I never will be.  I know Jesus died for my sins and want him to be my Saviour.  Just this past week I confessed to a preacher I have doubts sometimes and it’s like he attacked me.  Made me feel like If I can’t believe I am saved, then I wasn’t.

I often deal with people on this issue. Sometimes our feelings get in the way of our faith. But this does not mean that we are lost. Even saved people struggle with doubts and some struggle more than others.

1 John 5:13These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life, and that ye may believe on the name of the Son of God.
See All... states, "These things have I written unto you that believe on the  name of the Son of God; that ye may know that ye have eternal life, and that ye may believe on the name of the Son of God." John is convinced that the people he is writing to have believed. However, he is still writing so that they may know that they have eternal life. They must have had trouble with doubts.

Consider this. The only way a person can absolutely know that they are saved is to absolutely know that their salvation does not at all depend on them. It is not what we do but what Christ has done. Technically speaking, it is not the prayer or any external action of ours that saves us. It is the completed work of Christ on the cross and our faith in God on the basis of that work.

And even our faith does not have to be perfect. We believe to the best of our ability and our faith is completed by the faith of Jesus Christ (Galatians 2:16Knowing that a man is not justified by the works of the law, but by the faith of Jesus Christ, even we have believed in Jesus Christ, that we might be justified by the faith of Christ, and not by the works of the law: for by the works of the law shall no flesh be justified.
See All...). I have a section on the faith of Christ in the article called "How to Lose Your Salvation".

As to feelings, I know that these can be terrifying. However, you must understand that feelings do not save us and feelings cannot make us lost. Any honest saved person will tell you that there are days that he or she does not feel saved. They only accept that they are because of the promises of God in His word.

May the Lord bless you as you seek the assurance that He wants you to have. Cast yourself entirely at His mercy and consider how such a wonderful God would certainly accept you in your distress. I have, at times of doubt, told the Lord that if He sends me to hell (though righteously I belong there), He will have to send me believing in Him to the best of my ability and totally relying on His grace and mercy. God has used these times of frankness with Him to renew and strengthen my faith in Him. I pray He will do the same with you.