10 Commandments, Psalms, and Scripture

For it needs must be that whoever knows the Ten Commandments perfectly must know all the Scriptures, so that, in all affairs and cases, he can advise, help, comfort, judge, and decide both spiritual and temporal matters, and is qualified to sit in judgment upon all doctrines, estates, spirits, laws, and whatever else is in the world. And what, indeed, is the entire Psalter but thoughts and exercises upon the First Commandment?

A confession: Luther often says this, that in understanding the 10 commandments perfectly, one knows all the Scriptures. I find this saying as enigmatic as many I read in the works of Eberhard Jüngel. I mean, on the one hand, I "get" it. On the other hand, it seems counter-intuitive, from the Christian understanding of Scripture, to see the 10 Commandments at the center.

I get his 2nd point more clearly- the psalms are indeed thoughts and exercises upon the First Commandment. It is a fruitful exercise to read any given psalm, and think of it in this way. It forces a much more creative and relational approach to God and our relationship to this God. God is a jealous God. But the psalmist is also a jealous crooner, singing out songs to God that demand as much as God demands in His righteous commands. In fact, this parallel is profound- the jealousy of God parallels the prayed frustration of the psalmist when he/she cries out, "Why are you so far from me, O Lord."

But how is it that we should understand the 10 Commandments as comprehending all of Scripture. Don't we need to say more than this? If Christ is in the 10 Commandments, does this demand a category shift, a new way of knowing Christ, or at least reading the relationship between Christ and the "old" testament as summarized in the commandments.

Which leaves me further asking (a question I seldom ask myself, even in my best moments), why is it that we are so involved in the salvific work of Christ in our theology, but only marginally involved with this teaching of Christ, "love the Lord your God, and love your neighbor as yourself." It occurs to me that as a theologian I need to spend time writing a theology of the law. Or, better yet, reviewing this section of the catechism daily.