Matthew 5:27, 28; Adultery being sin, but fornication justifiable?

[XVII]

Matthew 5

27Ye have heard that it was said by them of old time, Thou shalt not commit adultery: 28But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart.

I have a dear friend who uses these two verses to justify that it is okay to look upon a woman and lust after her in his heart and mind.

Is this justification okay? If so, prove it. If not, explain.

 

[JohnJones]

Your friend says that since he is single it is ok to lust after single women because it is not adultery? When Jesus spoke the above words, he was not merely saying this is the way it is for this sin but also showing a principle that we are to cleanse our hearts and not be like "I sure would love to do this sin but I'm not going to" - rather we need to not only not do it but hate it too.

 

[Theophorus]

With in the context of the Law and the new testament, there are two main classes of sexual immorality, fornication and adultry. Fornication is sexual activity outside of the bounds of marriage, either married or unmarried. Adultry is when a married person fornicates. The passages in scripture apply both to men and women but often times seem diected at men in paticular.
Assuming your friend is not married, he is guilty of fornication in his mind and heart. Though the verses in question do not paticularly describe this situation, it applies. To say otherwise would be to ignore all of the other teachings of scripture on immorality. Your friend is forgetting the teachings of Paul on one of the purposes of marriage, which should be entered into so that a person does not become tempted to fall into fornication or be carried away by lust.
It is also a very legalistic way of interpreting scripture, for example, as long as I get drunk from vodka or beer and not wine, I am acting in the strictest sense of biblical teaching is ludicrous.

 

[XVII]

so how can i convince my friend that this verse is applying also that it is wrong to look upon a woman (or man if you are a woman) with a lustful eye?