13 "Foods for the stomach and the stomach for foods," but God will do away with both of them. The body is not for sexual immorality but for the Lord, and the Lord for the body. 14 God raised up the Lord and will also raise us up by His power. 15 Do you not know that your bodies are the members of Christ? (D)So should I take the members of Christ and make them members of a prostitute? Absolutely not! 16 Do you not know that anyone joined to a prostitute is one body with her? For it says, The two will become one flesh. 17 But anyone joined to the Lord is one spirit with Him.
18 Flee from sexual immorality! "Every sin a person can commit is outside the body," but the person who is sexually immoral sins against his own body.
1 Corinthians 6:13-18 (Holman Christian Standard Bible)
This passage certainly makes sexual immorality seem like something God definitely doesn't approve of. Let me state, that I certainly believe in reading scripture within its context (both historical and otherwise), however, I don't think there's any way to "side step" this verse so to speak. I feel it's pretty clear: God does not approve of sexual immorality. The thing that I think is interesting is how it states that sexual sin is a sin committed against one's own body. I think a lot of Christians use the excuse of "I'm not hurting anyone," to justify having sex with their boyfriend/girlfriend. Ok, you're not hurting someone like you hurt someone when you lie, but you are certainly hurting yourself, and you are sinning against God. Some translations translate the words "sexual immorality" as "fornication." However, the immorality specifically mentioned in this passage is prostitution. This does not mean that fornication is not also considered immoral: