Anyway, here's how the Westminster Larger Catechism explains the first commandment. Though it does not make the explicit link with justification by faith, it's still wonderful and stirring.
Question 104: What are the duties required in the first commandment?
Answer: The duties required in the first commandment are, the knowing and acknowledging of God to be the only true God, and our God; and to worship and glorify him accordingly, by thinking, meditating, remembering, highly esteeming, honoring, adoring, choosing, loving, desiring, fearing of him; believing him; trusting, hoping, delighting, rejoicing in him; being zealous for him; calling upon him, giving all praise and thanks, and yielding all obedience and submission to him with the whole man; being careful in all things to please him, and sorrowful when in anything he is offended; and walking humbly with him.If we were to do that, would there be any need for any other commandment? Luther recognized--no.