Throughout this book, emphasis has been on obedience. The Lord commanded obedience (6:24) and Israel was to be careful to obey (6:3). Blessing was dependent on obedience (11:13,27).
At Sinai, Israel had agreed to the covenant stipulations. But after she entered the promised land, there was to be a formal meeting on the side-by-side mountains of Ebal and Gerizim – half of Israel on one mountain and half on the other. There, the priests were to recite the blessings of the covenant and the conditions of the covenant and Israel was called to formally agree to them once again.
Why the formal emphasis? Because God was and is serious about the behavior of His people.
There are many other laws not recited in Deuteronomy 27. It doesn’t mean the unrepeated laws were unimportant, but these give us some insight to the concerns of God. Note that God is concerned about idolatry, about respect for the family and other people’s property, about the treatment of the helpless and respect for life. Significantly, four of the twelve statements have to do with sexuality. When outsiders complain that Christians are far too focused on sex and not on other things like justice, mercy, and kindness, we would do well to remember that sexual sin is not only sin against God, but against ourselves and against others. And besides all that, it is of tremendous significance to God. Sexual sin ruins families, destroys integrity and is also addictive. Sexual sin is not insignificant but is, in God’s eyes, of overwhelming concern. If our society can dismiss so casually these morals that are so tied to character and a harmonious community life leads inevitably to the question: “how quickly might it cast off all morals?