The Karezza Method, by J. William Lloyd [1931], at sacred-texts.com
Sex is very close to soul. Whoso touches sex touches the secrets and centers of life. This is the Mid-Spot, the Origin, the Crux, the Mystery. In sex the soul is naked. At the contacts of sex the soul trembles, quivers, is shaken to its midmost. The voice of sex, in its power, is as the voice of God - the most imperious and certain-to-be-obeyed call known in Nature or to man.
Sex, soul, religion, morality, are not to be separated. They belong together. The first reverence we detect in Nature is that of the male for the female, of offspring for mother. There is fear elsewhere, but here are mysterious adumbrations and blendings of attraction, adoration, worshipful obedience and withdrawing respect. Sex-religion was the first religion of man and we shall never get back again to true religion until we again see God in His creative motions and worship and reverence the soul in flesh.
Sincerity, seriousness, cleanness, generosity and liberty in sex are the foundations of morality. Where these are found we have genuine love, true relations, open souls, fearless hearts, fragrant bodies, healthy children, happy mothers, a society everywhere honest, free and kind. Where these or any of them are lacking, society rots, lies fester, men exist by crime, and shame broods like a cloud.
The agitation of the youth who blushes, trembles and stammers before the woman he loves; of the girl who melts in his arms, not daring to lift her eyes, dumb, soul-shaken, overcome by the mystery of her being and emotions - these reveal by signs ineffable the sacred seriousness of sex.