The Institutio [John Calvin’s Institutes of the Christian Religion] is also one of the wonders of the spiritual world – the world of doxology and devotion, of discipleship and discipline, of Word-through-Spirit illumination and transformation of individuals, of the Christ-centered mind and the Christ-honoring heart. Shaping all its elaborate doctrinal discussions, with their rigorous biblicism, their strong assertions of divine sovereignty, and their sharply focused trinitarianism, is a persistent orientation to the conscience, a contagious awareness that we do and must live our lives coram Deo, in the presence and sight of the searcher of hearts, and a drumbeat insistence that sound belief must express itself in pietas, faithful – that is, faith-full – obedience to, and worship of, the Father and the Son through the Spirit. Though the Institutio became more than a catechism in that it reached beyond the basics of the discipling process, it nowhere became less than a catechism by losing its discipling focus as the permanent bottom line. The exposition of Jesus Christ as set forth in the Creed, and of the Christian life, of the Ten Commandments, and of praying the Lord’s Prayer, stands out in the ongoing flow as (to change the image) jewels in the crown.
From: “Forward” by J. I. Packer, in A Theological Guide to Calvin’s Institutes: Essays and Analysis, edited by David W. Hall and Peter A. Lillback; The Calvin 500 Series (Phillipsburg: P&R Publishing, 2008), p. xi.