Many Christians want to compromise with sexual sin. They don't really want to be that holy or set apart. They want to flirt with sin and see how much they can get away with. God tells us in I Thessalonians 4:3 what His will for us is in this area, "For this is the will of God, even your sanctification, that ye should abstain from fornication; That every one of you should know how to possess his vessel in sanctification and honor; Not in the lust of concupiscence {sensual longing}, even as the Gentiles which know not God."
God wants us to be holy and set apart from sin. When young people ask, "How far can we go before marriage?" they are asking the wrong question. It should be, "How can I be holy and more excellent in this relationship before marriage?" Our aim in life should be to learn how we "ought to walk and to please God, so we would abound more and more," not "How far can we go away from God's ideal?"
We live in a sex crazed society. God tells us that sexual sin should not even be named among us, not even a hint {Ephesians 5:3}. He warns us to flee sexual immorality and to keep the marriage bed undefiled {Hebrews 13:4}. So instead of trying to figure out close you can get to sin, make it your goal to see how far away from sin and how close to obeying God's commands you can get.
Even our thought life should be taken captive to God, every thought {II Corinthians 10:5}, for out of our thoughts come our actions. Christian brothers and sisters, stop flirting with sin. Stop entertaining it in any way. God doesn't give us these commands to hurt us but to help us and to make us more joyful, living the abundant life He died to give us.
God's ways will always be best. If you are in a dating relationship or even engaged, stop trying to figure out how far you can go and seek to honor God in every area of your life. If you are married, seek to honor God in your thought life as well as in all of your behavior {what you watch on television, what you read, what you listen to, etc.}
Let us be Christians who are sanctified, set apart, and holy unto God. Don't sink in the mud and muck of this world. Instead, give yourself a good hosing off and begin obeying God, pleasing Him in everything. FLEE sexual immorality! {I Corinthians 6:18}