Let's review two context or otherwise.
Masturbation. Does it honor God? No. Nor does stuffing yourself with donuts and destroying your body with alcohol. Did God intend for us to use our bodies like a musical instrument? No. So bad advice.
I've heard this type of argument a lot. It comes from the passage I was just discussing in 1 Corinthians 6. That passage is talking about idolatry and the temple imagery is very suggestive of this idea. Paul says the corporate body of believers are not only the members of Christ but are also the temple of the Holy Spirit. Most people don't notice that the Greek word for "you" in 1 Corinthians 3:16-17 is plural and the word for temple is singular.
Together we are the temple, not individually. God doesn't have millions of little temples running around. Peter uses a beautiful metaphor for this spiritual reality. He calls believers "living stones" who are being
built together into "a spiritual house for a holy priesthood" (1 Peter 2:5).
Do you not know that you (plural) are God’s temple and that God’s Spirit dwells in you (plural)? If anyone destroys God’s temple (singular), God will destroy him. For God’s temple is holy, and you (plural) are that temple (singular).
It helps to understand the situation in Corinth and how the pagans worshiped in their own temples. They would sacrifice an animal in front of the idol, they would then cook it, serve it on a feasting area/table adjacent to the temple, the idol was invited to be the guest of honor, they would eat and drink, and then have sex with temple prostitutes. Paul makes reference to this outline in 1 Corinthians 10:7 (
"play" is a euphemism for sex). This common association in the larger culture would explain why sexual immorality and idol food are also always linked in the New Testament (i.e. Acts 15:29, Revelation 2:14, 20). This is why engaging in corporate idolatrous activities, such as having group sex with temple prostitutes (1 Corinthians 6) and eating food sacrificed to idols in public (1 Corinthians 10) was not glorifying or honoring to the holy corporate "body" in which all Christians are member of, namely, the temple of the true God. In this way, 1 Corinthians 6:18 actually makes sense.
Every other sin a person commits is outside the body, but the sexually immoral (inappropriate contenteuo) person sins against his own body.
Note that the word "other" is not actually in the Greek, but is artificially added by many translators (ex. ESV, NIV, and NASB) because they can't make sense of the verse without it. However, when temple prostitution (inappropriate contente) is made the context of v.18, it makes sense as Paul originally wrote it. The only sin that can affect the
inside of a believer's "corporate body" is one where he attempts to mingle his religious allegiance with another deity (idol). Again Paul makes the same argument in chapter 10, but this time with food. While strong Christians could eat such meat in private (because the meat by itself is nothing but meat), they were not allowed to do this type of activity in front of weak Christians or in the idol's temple. We see this all through chapter 9 and 10. Public association was the sin.
In short, honoring God with our actions involves the context in which those activities occur. The better question would be "Does this dishonor God?". Otherwise you're left with other odd questions, like "Does defecation honor God?", "Does vomiting honor God?", "Does driving a car honor God?", or "Does sleeping honor God?" None of those make any sense - just like your masturbation question. Masturbation is a healthy activity if done in moderation.
Sex outside of marriage. Clearly not supported in the NT. Any sexual relations outside of the one man one woman marriage is fornication and against God's design (Matthew 19:1-12).
Matthew 19 is about divorce and marriage. Not about sex. Being "one flesh" has no sexual connotations. It just means having a kinship bond with your wife. I have a whole thread on this if you want to read it:
One flesh
In that same thread I responded to Matthew 19:9:
Divorce "except for inappropriate contentea"
Do you believe that Jacob was in sin when he slept with Rachel? She was Jacob's second wife.
Do you believe that David was in sin when he slept with one of his concubines? They were not his wives.
I will need to know what you mean by "ethically produced inappropriate contentography."
I'll give you an example we can both probably agree on: A Christian heterosexual married couple video tape themselves have sex in private. That end product is ethically-produced inappropriate contentography.
