For all the girls who read my Blog, and for all the boys who read it and have sisters, these are some links and articles about modesty and guarding your heart:
By my dad:
Fashion today is a great example of the fact that in our "free" society, we have very little choice. Girls' tastes are not their choice, they have been brainwashed by models, musicians, marketing (what is advertised and made available in stores), and moviestars into valuing a particular style of dress that is readily available. This is in fact cultural, and varies from place to place (when I was in high school, the jeans my cousin liked in Colorado, Uncle Tim and I thought were "ugly" and unattractive, in Washington). Styles change quite regularly - again driven by models, musicians, moviestars and marketing.
The further the society drifted from the Lord in the west, the more there was a conscious effort to wear away at society's values of what kind of clothes are acceptable: how much skin is shown and how tight the clothing is. In less than a century, we went from ankles, wrists, and upper neck to strap bikinis. Girls who wouldn't walk around at school in their underwear, will wear swimsuits more revealing than underwear at a pool party and not see a contradiction! At the same time, fathers and pastors lost influence to equality (fathers have no special authority) and relativism (what is right and wrong is relative to your situation - no absolutes), and even worse, men are captivated by the female body and many are quite happy to see more revealed. What kind of a person do you want to look at you or be attracted to you? A man who is quite happy to have used, worn merchandise (though he will still find many features to praise and say you are precious, as he told the last and the next one), or one who only prizes a valuable, guarded protected treasure (who himself wants to guard himself for his wife, though he struggles with all that is offered up before him in uncovered bodies)?
Today when all kinds of dress are (1) available, and (2) accepted by peers, the issue of modest dress truly becomes a matter of relenquishing one's rights ("I CAN wear that, but because I value my body as a treasure to be adorned for my husband, and because I have the power to unnecessarily cause guys to sin against the Lord by tempting them with the lure of my curves to lust, I choose not to").
The modesty thing is primarily "one way" (affecting girls' dress more than guys) because a guy's dress is typically not a means to make a girl stumble and sin. A handsome guy with his shirt off may be attractive, but the attraction won't lead to a temptation that is sensual in nature, more likely a desire to be cherished and protected by his strength, and to be seen with him, which could lead to a temptation for her to use her feminine abilities, flirtation, and immodesty, to capture him. The same could happen with his football gear on!
About guarding the heart, the quoted passage about guarding your heart is from Proverbs 4:23 but in the chapter "My son" is addressed 3 times. It applies to daughters, but is addressed to son, and how he should walk in wisdom and hold fast to instruction that will give him healing in life. He should look straight ahead and not swerve to the left or right (25 - 26). The next 3 chapters are all about sexual sin - though mostly about faithfulness to his wife and withstanding the temptation of the aggressive woman, rather than not defrauding another girl.
The command most applicable to young men is: 1 Timothy 5:1-2, where Paul instructs Timothy to treat younger women like sisters, in all purity. What should a guy do when tempted: FLEE! At the very least this means "fleeing" with his eyes (or as one book says, "bouncing" his eyes and looking elsewhere). 1 Corinthians 6:18 "Flee from sexual immorality. Every other sin a person commits is outside the body, but the sexually immoral person sins against his own body." and 2 Timothy 2:22 "So flee youthful passions and pursue righteousness, faith, love, and peace, along with those who call on the Lord from a pure heart." This fleeing is the application of the bad example given in Proverbs 7. A girl or guy should also flee a situation where conversation (jokes, stories, tales of experience, etc) or movies have a hint of sexual immorality.
"But among you there must not be even a hint of sexual immorality, or of any kind of impurity, or of greed, because these are improper for God’s holy people. 4 Nor should there be obscenity, foolish talk or coarse joking, which are out of place, but rather thanksgiving. 5 For of this you can be sure: No immoral, impure or greedy person—such a man is an idolater—has any inheritance in the kingdom of Christ and of God. 6 Let no one deceive you with empty words, for because of such things God’s wrath comes on those who are disobedient. 7 Therefore do not be partners with them.
8 For you were once darkness, but now you are light in the Lord. Live as children of light 9 (for the fruit of the light consists in all goodness, righteousness and truth) 10 and find out what pleases the Lord. 11 Have nothing to do with the fruitless deeds of darkness, but rather expose them. 12 For it is shameful even to mention what the disobedient do in secret. " (Ephesians 5:3-12)
This is our standard, not what others do or allow. The reason we care is because we want to please the Lord, not ourselves.
One last note: www.therebelution.com is working on a Modesty Survey. I suggest checking it out. Personally, I can't wait for the results to come out.