Last week I received an email from a woman wondering about the best way to break up with her unbelieving boyfriend. She wrote,
I have decided to break up with my non-Christian boyfriend. Should I tell him that my main reason for doing so is his lack of faith and thereby risk turning him off to Christianity forever? Or should I withhold this information so that he won't associate my faith with the pain of being dumped?
I care a lot about him, and I definitely want him to find God on his own someday. I'm just afraid that I will do or say something to jeopardize his journey. Is there a way to do this kindly and honestly without damaging his view of God?
I love getting questions like this, especially when they're full of faith in the God who convicts us of sin and gives us strength to obey. I replied,
I'm so thankful you're willing to do what's painful in order to obey God's Word (1 Corinthians 7:39, 2 Corinthians 6:14). This is evidence of the Holy Spirit's conviction. You're right that how you do this is important for how he perceives God. I don't think you should tell him your main reason for ending your romantic relationship is his lack of faith, however. Instead, I think you should tell him it's yours. ...
It's not your boyfriend's fault that this is ending so much as it's your responsibility that it began. As the believer in the relationship, you are the one who knows what God requires. If you're trusting in Christ's atoning work on the cross, you have the Spirit of Christ within you to empower you to obey. Rather than telling him it's over because of a faith he doesn't have — and risk a false conversion or, as you fear, a reason for him to be bitter about Christianity — explain that you were wrong to date him once you knew he didn't believe the Gospel. Tell him you're sorry for misleading him about your faith.
You can read my full answer at Boundless.org.