No doubt from the earliest days of Christianity there have been men and women for whom the sexual relationship was illumined and deepened by the Christian message of love, for whom it expressed a true equality, an equal-sided valuation and respect, for whom coitus was an expression of tenderness and unity, not merely the gratification of animal urges. But it is one of the great tragedies of history that not until recent times has this implication of Christianity found public expression...
Sexual activity is essentially neither good nor evil; it is a normal biological activity which, like most other human activities, can be indulged in destructively or creatively. Further, if we take impulses and experiences that are potentially wholesome and in a large measure unavoidable and characterise these as sinful, we create a great volume of unnecessary guilt and an explosive tension within the personality. When, as so often happens, the impulse breaks through the restriction, it does so with a ruthlessness and destructive energy that might not otherwise have been there. A distorted Christianity must bear some of the blame for the sexual disorders of society.
Towards a Quaker view of sex, 1963