THE BEGINNING OF THE SO-CALLED "HOLINESS CODE" (Lev. 18) is full of interest. We should take note of at least four things:
(1) Just because this is the first time that some prohibitions have been articulated in the Bible does not necessarily mean that this is the first time anyone thought of them, or condemned the practices in question. Before murder is actually prohibited as such, Cain commits it, is condemned for it, and is punished. The same is true for many actions treated in the Law of Moses. Much of the Law of God is written on the human conscience, so that societies without Scripture erect moral structures which, however different from the values of Scripture, overlap with Scripture in important and revealing ways. Similarly, many of the prohibitions of sexual alignments listed here were doubtless already frowned upon; now their prohibition is codified.
(2) As usual, the commandments in this chapter are tied to the person and character of God (18:2-4, 21, 30), the Exodus (18:3), and the sanctions of the covenant (18:29).
(3) Many prohibitions in this chapter establish barriers in sexual relations: a man is not to have sexual relations with his mother or stepmother, sister or half-sister, granddaughter, aunt, daughter-in-law, sister-in-law, and so forth. Homosexuality is "detestable" (18:22); bestiality is "a perversion" (18:23). Tied to this list is the prohibition against sacrificing any of your children to the horrible god Molech, who demanded that some be burned in sacrifice (18:21); perhaps the common point is family integrity. Another striking element in this chapter is the fact that the perversions are prohibited in Israel so that this fledgling nation does not become as debauched as those they are about to displace — lest they head in that same direction and are vomited out of the land (18:24-30). The shadow of the exile hangs over the horizon before the people even enter the land.
(4) Intriguingly, Leviticus 18:5 is cited in Romans 10:5 and Galatians 3:10. The general point in both passages is the same. The "Law," i.e., the law-covenant, is grounded in demand: keep God's decrees and laws, and live.
This is not to say that faith isn't required, still less that the Old Testament covenant is not characterized by grace (not least in the sacrificial system, such that those who breached the covenant had a recourse to find a way back." But its heartbeat is demand. By contrast, the heartbeat of the new covenant, like the covenant with Abraham, is above all characterized by faith (whatever its demands). Whatever the overlap, the distinctive heartbeat of the two covenants must not be confused.
Leviticus 18; Psalm 22; Ecclesiastes 1; 1 Timothy 3