Sex outside of marriage is a sin. But what about "less than sex"?

                             "How far is 'too far'?"

In the days of horse-drawn carriages, a wealthy man was looking for an expert driver to take him on his many business trips. Looking for only the most experienced drivers, he narrowed the applicants down to the two most experienced men. All that was left was to have each man demonstrate his prowess with the prospective employer as a passenger.

The first man was certainly expert, and his handling of the horses and the carriage was deft and flawless. When driving on a narrow path with a sharp drop-off, however, the driver, as if to show off his superior skill, steered as closely to the drop-off as he could.

The second applicant's skill and expertise were also quite apparent. Driving on the same narrow path with the sharp drop-off, however, he appeared to steer the carriage as far from the drop-off as possible.

Guess who got the job?

I have two points to make. The first is that the sexual act is one of the most amazing gifts God has given us. It brings two people closer together both physically, mentally, emotionally and spiritually. It ties hearts and minds together and helps build unbreakable bonds of trust upon which stable families can be built. It is not the end-all and be-all of a strong marriage, but it is one of the most powerful tools we have been given to use for this purpose. Let me reiterate: sex inside the marriage covenant brings about an intimacy and trust between the two that is unmatched by any other experience.

My second point to make is this. You have to understand what sex is. It is not simply the act of intercourse. Sex begins with flirting which communicates that the two find each other attractive. Sexual tension and desire begin to develop and the two people find ways to be near each other, enjoying the rush of the endorphins and such that flood the brain. When they begin becoming physically intimate, they spend time in foreplay allowing the sexual tension to build. Intercourse is the culmination of this process of bringing two people so close together they are willing to share themselves so completely.

When did the sex begin? Intercourse was at the end, and it was only part of the whole experience.

My concluding thoughts: If you are married, when can you tell your spouse is interested in sex? Often it is when they are playful and flirty with you. Sex starts with the flirt. If you are married, then flirting outside of marriage is off-limits. If you are married, seeking or enjoying sexual stimulus without your spouse is wrong, because it weakens (or destroys) the trust and intimacy shared between only you two. This is why Christ said that even lusting after another is adultery.

But what if you aren't married yet? Well, flirting is ok, because that is how we signal the other person we are interested in moving the relationship in a more serious direction than just friendship.

Now when you do meet and fall in love and marry the true love of your life, do you want to say to them (or do you want to hear them say), "I have already shared this sacred gift of intimacy with others before you. What we have is wonderful, but it won't be unique in my life because of my past decisions."

Sex is ordained of God between those who are married. Flirting is part of courtship. But anything that stimulates you sexually must be avoided unless it is with your spouse. If you don't have a spouse yet, then continue to avoid it.

I would answer Matthew 5:27-28 sprinkled in with the stern warning of Matthew 23:25-26. The later reminds us external observance, or doing the minimum to get by with is not enough, it is what comes from the heart. The former passage speaks to the urges of the heart given at the Sermon on the Mount.

Without even turning to a scripture (I could pull many out of my hat so to speak), it comes down to simple logic for me (personally).

If you were a fish, and you saw tasty food attached to a line, knowing it could lead to you getting hooked and potentially becoming someone's dinner, would you go for the tasty food, or avoid it to save your life?

Similarly, would you engage in activities that could lead you to the "hook" of crossing the line, just because it makes you feel good? Or would you rather avoid taking such a risk, and wait till you are safe to go for what satisfies?

A logical answer would be to wait until it is safe, and avoid going for what would put you in danger.

I think Matthew 5:27-28 sums it up well, by setting the standard not at sexual immorality, but even at the thought of sexual immorality.

Therefore, if lusting after a woman is sin, then surely "less than sex" outside of marriage in a lustful context, is also sin. This means that even kissing, holding hands, or hugging could be sin, if it is done lustfully.

I suspect you're driving more at issues like heavy petting, oral sex, etc. For these things, I think Tom's answer is great, when he quotes 1 Corinthians 6:18. Fleeing from sexual immorality would suggest getting as far away from immorality as possible--not flirting with it as closely as possible without "crossing the line."

One definition of sin is "anything that does not glorify God," and as such, a simple test I often use in my life to decide if something would be sinful or not, is "Would __ bring glory to God?" In this context, "Would [whatever sexual act, outside of marriage] bring glory to God?"

You are asking the wrong question. Even tempting your mind to follow that line of reasoning will leave you open to temptation and making mistakes that need not have been made.

Don't imagine that there is a line in the sand that you magically cross if you do one action too much. Don't see how far you can go. Instead, flee. Run the other way. See how far you can get from the 'line', how far away from temptation you can place yourself. A man is told to stand against many things, and when all is done to stand firm still₁. Yet when it comes to sexual temptations the Bible says to flee₂.

The Bible counsels us over and over to be above reproach₃. It instructs us to avoid anything even resembling evil. It calls us to be holy even as God is holy₄.

The right question is, "How can I best keep myself and my partner as pure as possible?" When you find answers to that question, act on them.

1. Ephesians 6:13 (ESV) Therefore take up the whole armor of God, that you may be able to withstand in the evil day, and having done all, to stand firm.
   1 Corinthians 16:13 (ESV) Be watchful, stand firm in the faith, act like men, be strong.

2. 1 Corinthians 6:19 (ESV) Flee from sexual immorality. Every other sin a person commits is outside the body, but the sexually immoral person sins against his own body.
   Genesis 39:12 (ESV) she caught him by his garment, saying, “Lie with me.” But he left his garment in her hand and fled and got out of the house.

3. Colossians 1:22 (ESV) he has now reconciled in his body of flesh by his death, in order to present you holy and blameless and above reproach before him,

4. 1 Peter 1:16 (ESV) since it is written, “You shall be holy, for I am holy.”

1 Corinthians 6:18 comes to mind which says "Flee from sexual immorality. All other sins a person commits are outside the body, but whoever sins sexually, sins against their own body"

I think this is telling us that asking "where is the line and how close can I get to it" is not the right way to think about it. Rather that we should be seeking to avoid sinning sexually.

We are all tempted in different ways so fleeing means different things.