We live in a society that does not encourage delay of gratification.  Why should we wait for anything?  How does being sexually abstinent prior to marriage provide any benefit other than being frustrated?  

The Gemara on amud aleph quotes a verse in Psalms (114:12) which by way of derash equates behaving modesty and remaining chaste until marriage to building the Temple.

״מְחֻטָּבוֹת תַּבְנִית הֵיכָל״ — אֵלּוּ וָאֵלּוּ מַעֲלֶה עֲלֵיהֶן הַכָּתוּב כְּאִילּוּ נִבְנָה הֵיכָל בִּימֵיהֶן.

The Gemara returns and interprets the final phrase of the verse: “Carved after the fashion of a palace”; the verse ascribes to both these and those, the young men and women who vigilantly preserve their modesty, as though the Sanctuary were built in their days.

Any worthwhile endeavor takes hard work and sacrifice.  Material or intellectual success does not come by being passive.  Most businesses or professional developments take years of devoted work.  Why should spiritual matters be any different? Psychologically speaking, this is an inescapable truth.  Today, this is being cast into doubt even in regard to material success. With an increase in socialist rhetoric and trends in our country, even the ethic of hard work paying off is being challenged by the idea of “free”, “handouts” and getting something for nothing.  

While any particular religious sexual restriction can be debated on intellectual grounds, the psychological importance of these taboos are unmistakable.  The sexual drive is too powerful for society to function without some regulations in place to channel it appropriately.  For example, the incest taboo is universal in all cultures throughout the world and history, as defined as prohibiting marriage between certain close familial members.  The obvious psychological reason is that the overpowering sexual drive, combined with the all-too-convenient availability of sexual partners within one’s family, would lead to too many abuses of power and relationships.  Any culture that allowed incenst, would destroy families and marriage.

While secular people may think of religion’s sexual prohibitions against pre-marital sex or masturbation as primitive and unnecessarily depriving, ultimately it is about respecting the power of sexuality and its ability to overpower and distort everything else.  Managing one’s sexual impulses in a healthy and balanced manner is the road to sexual fulfillment and harmony in marriage.  Using the power of the sex drive in order to concentrating love, attention and resources into one partner is key.  That emotional and developmental skill takes years to master. If one does not develop it early in youth, it does not necessarily spontaneously grow later after you sowed your wild oats.  

This is why the Gemara compares sexual modesty to building a sanctuary.  In the space created by moderated and managed lust, you will find the ability to build an emotional sanctuary in a marriage and in the world.