Lewis on Lust, Sex

Why has sex become man’s chief stumbling block?’ But has it? Or is it only the most recognisable of the stumbling blocks? I mean, we can mistake pride for a good conscience, and cruelty for zeal, and idleness for the peace of God et cetera. But when lust is upon us, then, owing to the obvious physical symptoms, we can’t pretend it is anything else. Is it perhaps only the least disguisable of our dangers. At the same time I think there is something in what you say. If marriage is an image of the mystical marriage between Christ and the Church, then adultery is an image of apostasy. Also, all the sexual vices have this unfair advantage that the very temptation is itself pleasurable: whereas the temptations, say, to anger or cowardice, are in themselves unpleasant.