" You are not conscious of having grossly violated any moral low. But have you never heard of a gentleman in India who had a tame leopard that went about his house? It was as playful as a cat, and did no one any harm till one day, as he lay asleep, the leopard licked his hand, and licked until it had licked a sore place and tasted blood. After that there was nothing for it but to destroy it; for all the leopard-nature was aroused by that taste of blood. And some of you young people, with all the godly associations that are round about you, will — I am always afraid — get a taste of the devilry outside, of the world’s vice and sin; and then there is the leopard’s nature in you. If you once get the taste and flavor of it, you will be prone to be always thirsting for it. Then, instead of the hope we now cherish, that we shall soon see you at your parents’ side, serving Christ — see you take your father’s place, young man, in after-years — see you, young woman, grow up to be a matron in the Church of God, bringing many others to the Savior — we may have to lament that the children are not as the parents, and cry, “Woe is the day that ever they were born. "
― Charles Haddon Spurgeon , Spurgeon's Sermons Volume 63: 1917