I am 21 male and I have been walking with the Lord for about three years with my fiancee. I love her, and I admit that we fell into temptation and began sexual relations. I can admit that, as a man of God, I put her first and the Lord second. With that said we both did.
Now I need some advice. I'm heartbroken. I caught her emailing another guy and writing to him things that broke my heart. For example she said to him, "If you where here and expressed your feelings toward me, I would not get married." They kissed while we dated but never slept together. She is crying for forgiveness and that he meant nothing to her and acted in the flesh. She cries that those emails meant nothing; that she knows I'm the man God put in her life. I'm her first boyfriend. We were high school sweethearts. I love her dearly, but the thought of another man kissing my love angered me, and I broke up with her. She hasn't stop calling nor texting. She wants to try this again and put God first rather then us putting each other above God. I understand that as a man in a Christian relationship, I failed, but do I forgive such acts?
"Do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived. Neither fornicators, nor idolaters, nor adulterers, nor homosexuals, nor sodomites, nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners will inherit the kingdom of God" (I Corinthians 6:9-10).
Being a fornicator and claiming to be a faithful Christian at the same time are incompatible ideas. "For this you know, that no fornicator, unclean person, nor covetous man, who is an idolater, has any inheritance in the kingdom of Christ and God. Let no one deceive you with empty words, for because of these things the wrath of God comes upon the sons of disobedience" (Ephesians 5:5-6). You weren't in a Christian relationship, you were in a worldly one. I'm point this out because you need to straighten out your life with God first. Nor can you take the high road and claim that you are guiltless in this relationship.
I don't blame you for breaking off the relationship. A marriage is supposed to be built on trust (I Corinthians 13:7), but she severely damaged that trust by chasing after another man while she was dating you. It reveals a character flaw that might remain during marriage.
Whether you forgive her is not an option. "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). You have to let go of your anger against her. Neither one of you have been faultless; thus, your own forgiveness from God rests on you forgiving her (Matthew 18:21-35).
But whether you decide to continue dating her is a separate issue, though it will be hard to see them as separate. There are two problems here. First, you have been too intimate with each other. It will be difficult pick up where you left off and not have sex until after you are married. It is not that it is impossible, but it will be a strain. There will be the temptation to "prove" that you are just as close as you were before, but you had let love and closeness be defined by physical actions. The second problem will make the first worse. Because she proved to have a roving eye, there question of whether she really has changed will be present. Such a question can only be answered over time. I would strongly suggest that if you decide to return to dating her that you don't get married for at least a year. If you are in college, it might be best to wait until you have finished your degree, so that you will be in a position to better support her when you do marry. Yet, that delay means you will be struggling with sexual temptation for a long while.
I can't make the choice for you. It is only something that you can decide. But whoever you date in the future, keep your pants on until after the wedding!
Thank you. Your words are of great help. God bless you.