One of the elements of late medieval Scotist and nominalist theology that had a profound impact on Luther was its denial of any analogy between God and man and its consequent recognition of the impossibility of formulating a rational metaphysic concerning God. All knowledge of God must rest on authoritative testimony, primarily on that of Scripture. Luther not only denied any recourse of theology to an analogia entis between God and man and insisted on the necessity of scriptural revelation, but also argued, in the light of his denial of human merit and his sense of the immediacy of Christ as revealer and savior, against any rational theologia gloriae that claimed to describe God as he is in himself and proposed that our earthly theology be a theologia crucis, conformed to the pattern of God’s revelation in Christ. Calvin, similarly, allows a glorious revelation of God in creation that ought to be understood by reason—but argues that human beings are so corrupted by sin that apart from salvation in Christ and the saving form of revelation given in Scripture, knowledge of God remains inaccessible to them. Calvin also distinguishes between the eternal Word and Wisdom of God and the revealing Word given forth in the words of the prophets, the latter being accommodated to human ways of knowing.
Muller, R. A. (2003). Post-Reformation Reformed Dogmatics: The Rise And Development Of Reformed Orthodoxy; Volume 1: Prolegomena To Theology (2nd ed., pp. 223–224). Grand Rapids, MI: Baker Academic.