GE 17:15-16, 20:11-12, 22:17 Abraham and his half sister, Sarai, are married and receive God’s blessings.
LE 20:17, DT 27:20-23 Incest is wrong.

What is the true issue here?  Is it that there is an inconsistency in the Scriptures, or is it that there is a misunderstanding of the nature of revelation on the part of the one who “found” the “inconsistency?”

Honestly, there is a mistake on the part of the one who thinks there is an inconsistency.

Morality takes different forms.  For example, homosexuality is immoral because it confuses the diversity that God intended to exist within the marriage relationship.  Fornication (pre-marital, or extra-marital sex) is wrong because it neglects that covenant commitment that God has designed to go along with marriage.  Incest differs from both.

Why does incest differ?  Incest differs because it does not violate any of God’s natural design for marriage.  Incest is prohibited later in Scripture.  Why?  It is prohibited by more recent revelation than creative revelation because of the fact of the fall and genetic issues.  Abraham lived close to the beginning of time.  Genetic problems as a result of the fall had not multiplied so much as they did later.  Thus it was that God waited to reveal His prohibition of incest at a later time, and could do so without being inconsistent.

One thing is definite: the prohibition of incest is like all other moral prohibitions; it is for our good.

  1. Loren says:

    Good post.

    A few days ago, I read a blog by a skeptic who posted a video clip of a Roman Catholic priest who was stumped by the notorious, “Where did Cain’s wife come from?” question.

    It seems that a lot of sincere Christians are often stumped by this dilemma when someone asks them about this. They don’t want to even consider or suggest the possibility that Cain was espoused to one of his own siblings because, as you cited, it contradicts the commandment of God given (much later)in the Law of Moses.

    Since even by the time of Abraham it was not considered taboo or even unusual that a man would be married to his half-sister, how much of a stretch would it really be to accept that siblings of the second generation to ever walk the face of the Earth (before virtually any of the genetic anomalies and mutations had entered the human race as a result of the Fall) would be able to marry and procreate?

    Anyway, good post, I just wanted to share that thought in line with the point you’re making. May the Lord richly bless you in your service to Him.

    In Christ,