The Definition of Faith in Luther and Calvin

How faith should be defined is an important theological question, and it is interesting in this regard to compare Martin Luther’s view of faith with traditional Reformed views of faith such as John Calvin’s.

Luther’s concept of faith is based on his dualistic anthropology. Just as the human person can be divided into body and soul, God’s word should be divided into commands and promises (Martin Luther, Works of Martin Luther: With Introduction and Notes [Grand Rapids: Baker, 1982], 2:317). According to Luther, God’s commands demand works, which can only be performed by the outer man or flesh. Contrasting with God’s commands are the promises of God, which demand faith. For Luther, faith is an action of the inner man or soul; therefore faith cannot be a work (Luther, Works, 2:318). Faith operates only in relation to the promises, and consists of trust in the promises of God (Luther, Works, 2:417). This command/flesh/works versus promise/spirit/faith dichotomy is the basic hermeneutical axiom in Lutheran theology. But in terms of faith, the significant thing is that, in Luther’s opinion, the object of faith is the promises of God.

On the Reformed side, the object of faith has traditionally not been limited solely to God’s promises. Faith for Calvin is primarily the knowledge of God’s mercy in Jesus Christ, but it also includes an acceptance of the other parts of God’s word. Summarizing Calvin’s discussion in the Institutes 3.2.1-43, faith is defined as “a knowledge of God’s will towards us, perceived from his Word” (John Calvin, Institutes of the Christian Religion [LCC 20-21; ed. John T. McNeill; trans. Ford Lewis Battles; 2 vols.; Philadelphia: Westminster, 1960], 1:549 [3.2.6]). In particular, Calvin identifies God’s “benevolence or … mercy” as being the core epistemological component of faith (Calvin, Institutes, 1:550 [3.2.7]). Faith is ultimately “a firm and certain knowledge of God’s benevolence toward us, founded upon the truth of the freely given promise in Christ, both revealed to our minds and sealed upon our hearts through the Holy Spirit” (Calvin, Institutes, 1:551 [3.2.7]).

But even though the knowledge of God’s mercy or “the freely given promise of God” is the core or “the foundation of faith,” Calvin denies that the knowledge of God’s mercy is the only component of faith (Calvin, Institutes, 1:575 [3.2.29]). “Faith is [also being] certain that God is true in all things whether he command or forbid, whether he promise or threaten; and it also obediently receives his commandments, observes his prohibitions, heeds his threats. Nevertheless, faith properly begins with the promise, rests in it, and ends in it” (Calvin, Institutes, 1:575 [3.2.29]). Thus, for Calvin, the object of faith is the whole word of God (not merely the promises), although the knowledge of God’s mercy in Christ as revealed through the promises is the focal point of the whole word of God, and hence the focal point of faith.