Without repeating the former observations on historic-cultural aspects of significance, it is of interest to observe again how the Corinthian church struggles with living in a culture which is against the ethical norm of Judaism and Christianity. Cult prostitution (if present) or any other kind of extra-marital sex (except what is mentioned in 5:1) was permissive and even encouraged in the Greco-Roman world.
Again we see Paul arguing against a false understanding of what it means to be free in Christ (vv. 12-14). In v. 12a Paul rejects (or better: further refines) the slogan that “all things are lawful” by stating that “not all things are beneficial.” This statement is probably not a slogan of the Corinthian believers, but which Paul applies to them. “Yes,” Paul implies, “all things are lawful but I will not be enslaved by anything.” Being free in Christ does not mean that the Corinthian Christians can live as they please.
The human body (v. 13) was created not for sexual immorality, but for the Lord (i.e. it is eternal). As God raised Jesus, in his body, from the dead so will He raise the believers from the dead (v. 14). The body matters!
If prostitution was prevalent in Roman Corinth, Paul now needs to argue against such (vv. 15-17). Since the body of a believer is a member of the body of Christ (v. 15a) this same body (and we only have one!) cannot be joined with the body of a prostitute (v. 15b).
It is to be said that sexual relationships between a husband and a wife create a “one flesh unity” (vv. 16-17) which is backed up with a Scripture citation of Gen 2:24: “Therefore a man shall leave his father and his mother and hold fast to his wife, and they shall become one flesh.”
Thus Paul needs to prohibit sexual immorality (vv. 18-20) – it is a sin against God. The Corinthian Christians need to flee from sexual immorality (v. 18a), since it is also a sin against their own bodies (v. 18b).
Here now Paul turns the corporate idea of the church being God’s temple into individualistic terms “Or do you not know that your body is a temple of the Holy Spirit within you, whom you have from God?” (v. 19). Believers have been bought with a price: they belong to God and thus must honor Him and Him alone (v. 20).
The problem of sexual immorality today is as prevalent as it was in the 1st century A.D. and we as a church need to address this issue. The church needs to educate her members in healthy ways about sex and communicate the beauty and God given pleasure of such. We hardly find sermons or Sunday school classes addressing those questions. One then does not need to wonder where “education” of sexual matters comes from.
Though we are free in Christ, there are ethical norms to live by. Yes, we are free in Christ, but we should not be enslaved by anything other than God and His righteousness (cf. Rom 6; esp. vv. 18 and 22).