There is included in God's words both an angry, threatening word and a friendly promise. He will horribly and terribly punish all who despise and transgress His commandments. Also, He declares how richly He will reward and bless those who hold them in high value and gladly live according to them. So God demands that all our works proceed from a heart that fears and regards God alone. From such fear the heart avoids everything that is contrary to His will, lest it should move Him to wrath. And, on the other hand, the heart also trusts in Him alone and from love for Him does all He wants. For He speaks to us as friendly as a father and offers us all grace and every good.
"You shall have no other gods before Me" [Exodus 20:3], in its simplest meaning states nothing other than this demand: You shall fear, love, and trust in Me as your only true God. For where there is a heart set in this way before God, that heart has fulfilled all the commandments. On the other hand, whoever fears and loves anything else in heaven and upon earth will keep neither this nor any of the commandments. All the Scriptures have taught these two things: fear God and trust in Him. The prophet David does this throughout the Psalms, as when he says "the Lord takes pleasure in those who fear Him, in those who hope in His steadfast love" [Psalm 147:11]. He is saying, "The Lord takes pleasure in those who have no other gods." (paragraphs 322-325)
Condensed from CONCORDIA: THE LUTHERAN CONFESSIONS, copyright 2005,2006 by Concordia Publishing House. Used by permission. All rights reserved. To purchase a copy of CONCORDIA, call 800-325-3040.