Where did Cain get his wife?

Scripture teaches clearly that all people are descendants of Adam and Eve, thus there had to be inter-marriage between brother and sister. There would have been no risk of this causing harmful deformities in the offspring, because mutations (accidental changes in the hereditary information) need time to occur and accumulate in a population. Thus the first few generations would have inherited perfect or near-perfect genes, largely undamaged by mutations.

In the pre-Flood world, harmful radiation from the sun and other cosmic sources was considerably more filtered than it is in the post-Flood world. Increased radiation and depletion of oxygen in the atmosphere (subsequent to the lowering of the atmospheric pressure) may have contributed greatly to man's rapid degeneration. With the passing of many centuries, many of these harmful, degenerative changes became added to the human race, so by the time of Moses it was absolutely necessary to have laws against incest, as were given to mankind (Leviticus 18-20).Today there would be even more chance of deformity/disease in the offspring of such a union than in Moses' time.

Additionally, because of the long life-spans (Adam lived to be 930 years old), Adam and Eve's descendants may have been numerous and widely dispersed before Cain even took a wife. Although all of the inhabitants of the land of Nod would have been descendants of Adam and Eve, who had many sons and daughters, Cain may not have married one of his sisters, but rather a descendant of one of his siblings.

Excerpt from The Answers Book, Revised Edition, by Ken Ham, Andrew Snelling and Carl Wieland, published by Master Books, 1992.

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