In your site you talk about how all forms of sexual activity is a sin and that the bible says that “all sexual activity outside of marriage is sin.” Please give me verses where this is true because all I can find is how intercourse is wrong outside of marriage. Please also explain how we can define fornication as any sexual activity, who defined this, and how do we know this is God’s definition. I appreciate your help.
If you do a word study on “fornication” or “immorality” (which are two ways the Greek work porneia is translated), you will find that it means illicit sexual activity. [Note: two very good web sites for doing Bible study are www.blueletterbible.org and www.studylight.org.] Many dictionaries will say “illicit sexual intercourse,” but that is unnecessarily narrow. Consider, for example, that Romans 1:29 condemns fornication in the same passage where lesbianism is shown to be sin. Since two women are unable to have sexual intercourse with each other in the same way that a man and a woman do, I believe it would be disingenuous to try and make a case that lesbian sex is not fornication or immorality simply because of physiology of sex prevents them from having intercourse.
Secondly, consider why it’s wrong in the first place: God is pure, and sexual activity outside of marriage is impure. God commands sex to be contained within marriage because it is so powerful; in fact, it is the glue that holds people together and binds their spirits to each other (1 Cor. 6:16).
Third, if one is trying to make a case that sexual activity short of intercourse is not sin, then I would ask, where do you draw the line? Ask the father of a teenage daughter if it’s sin for her boyfriend to touch her genitals, or if God allows this activity with His blessing. Ask the wife of a man visiting a prostitute of it’s OK for him to receive oral sex from her as long as they don’t engage in intercourse. And if you are bothered by our position that masturbation falls in the category of porneia, then I would reply that we have written so extensively on that subject that I’m not going to go further with it. I will say, however, that we recognize not everyone agrees with us on this issue. Nonetheless, we still have a hard time reconciling masturbation with Paul’s injunction to “do everything to the glory of God” (1 Cor. 10:31). Exactly how does one do that to the glory of God?
Hope this helps.