Few events have shocked the church quite the way the introduction of the anti-contraceptive pill did because, for the first time in history, sexuality became democratized and people finally had some control over their own reproduction, control that had previously been the dominion of the church.
With the sexual revolution of the sixties, and the general secularization of the zeitgeist over the last few centuries, orthodox traditional religious restrictions on sexuality (like their adherence to natural law theory and its injunctions against birth control, abortion and homosexuality), though still strongly supported by church officials, have been mainly ignored by the faithful, and the church has lost its grip on the conscience and soul of its constituents.
But is sex only about physical gratification, or is there some important spiritual component to it over which the church really ought to have something to say? Or can such components be achieved without it? Does the very idea of sex as metaphorical forbidden fruit enhance the sexual experience? Are atheists missing out?
And check out a brief summary of the history of the church and child sexual abuse.
Or check out the Unnatural History of Sex (The Revolution and Love).