I am having an issue with my engagement. Before I met my fiancee I was not a Christian. I had had sex with multiple partners. My fiancee, at times, has trouble forgiving me for these past sins. What can I do to help her? I know I've hurt her but don't know how to help her.
I'm assuming that you became engaged just recently, after becoming a Christian and after your sexual encounters. That being the case, your fiancee has nothing to forgive you about. You did not do her any harm; the harm you did was to yourself (I Corinthians 6:18). As an example, Paul had caused the death of a number of Christians before his conversion. "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" (I Timothy 1:12-13). Did this mean every Christian he ever encountered in the future had to offer him forgiveness for his past sins? I hope you realize that the answer would be "no."
Forgiveness is about releasing a person from their debt or obligation to you. The problem is that your fiancee is claiming a debt that doesn't exist. You can't change your past; you can only change yourself, and you did that already. Therefore, the only person who can change is herself. She has to accept the fact that you had a bad past, but that is not unusual for a Christian. She fell in love with the man you are today, and you became the man you are today in part because of your past.
I wonder if she realizes what she is saying. She is holding against you a matter that God has forgiven. Though there is no debt owed to her, she is saying she can't accept what God has done. "For if you forgive men their trespasses, your heavenly Father will also forgive you. But if you do not forgive men their trespasses, neither will your Father forgive your trespasses" (Matthew 6:14-15). I don't think any of us would really want to be opposing God.
I'm assuming that there aren't children involved who will impact your future, so that is not a consideration either.
So it comes down to her acceptance of you as a person, which includes the fact that you are a changed man. If she cannot accept this, she doesn't deserve you. I know this sounds hard because this is the woman you want to live the rest of your life with, but it is now, before the marriage, that these type of issues need to be resolved. If they are not settled, the marriage itself will be difficult.
Do you know of anything I can do to help her with that? Like certain passages or reading material? Also, how much detail is too much in regards to my sexual past?
You can share the answer I gave with her because then it is coming from a third party. It might be easier to accept since I don't stand to benefit one way or the other. Or you can summarize what I said and show her the passages I showed you. Or you can ask her to to write to me about her concerns.
The problem is there will be a natural inclination to compare herself to your past encounters. The fact that you aren't with them and are with her won't be readily apparent to her. Because of that I strongly suggest that you keep the information to a minimum. Acknowledge that they did happen, but also state that it was wrong and that you move away from that type of behavior when you became a Christian. If she presses for details, simply state that you don't want to dwell on the past. She doesn't need to know how many girls, how many times, or what was done.
As I said, if there is something that will affect your future together, that does need to be discussed. If you picked up an STD, and still carry it, she needs to know. If you have children because of your fornication, or that the possibility might exist, then she needs to know about the children.
Thank you, sir. I'll talk to her about what you said. Thank you for your help.