I'm really grateful for the various Reformed resources that are made available for free on the Net. One of the premier ones are those courses on iTunes U that seminaries make accessible. Just recently, I was able to download courses off Reformed Theological Seminary's offering, one of which was Dr. Rod Mays' course on Pastoral Counseling. His lecture entitled, "Sexuality," was a veritable blessing.
One of the concepts that I found most beneficial was the idea of sex as a foretaste of heaven. Christ and the Church are united now, not physically, but mystically, a union wrought by the Holy Spirit. However, when Christ comes back for His bride, glorified bodies will be given those who have been in such a union. Then, Christ and the Church will be together, forever to enjoy each other's corporeal presence. This is man's telos, and it is his greatest pleasure. Is it any wonder, then, that sex, if meant to be a foreshadowing of the future heavenly pleasure of Christ's physical oneness with the Church, is arguably the greatest physical pleasure that is possible to a human being presently on earth? This has ramifications for how a Christian views and treats sex in the now.
This view of sex tells me how good God is. It tells me that God loves me so much that He has given a means for me to have a glimpse of heavenly pleasure through the physical union of my wife and I in a way that glorifies Himself by being a metaphor of the union between Christ and the Church. It tells me that sex is utterly holy, and that giving in to sexual sin of any sort is really taking God's precious gift of heaven and treating it like dung, a profane thing. It tells me that my wife is more precious than I previously thought, for through her, God gives me a sneak peek of heaven. It makes me long more for that day when Christ shall come back for His wife, to be one with her, when heaven, and all its pleasures, shall be enjoyed in a glorified body. Finally, it tells me why the people of God are not given over to marriage in glory. This is so because the substance and reality pointed to by marriage and sex are finally established—Christ and the Church are now together physically.
In the lifelong war against lust, a view of sex as a foretaste of heaven may just be the straw that breaks the camel's back.