The first duty of man is to believe in God and to honor Him with his faith. Faith is truly the height of wisdom, the right kind of righteousness, the only real religion.
 Martin Luther, Commentary on the Epistle to the Galatians (1535). copy citation

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Author Martin Luther
Source Commentary on the Epistle to the Galatians
Topic wisdom religion
Date 1535
Language English
Reference
Note Translated by Theodore Graebner
Weblink http://www.gutenberg.org/files/1549/1549-h/1549-h.htm

Context

“Paul places the emphasis upon the two words: Abraham believed. Faith in God constitutes the highest worship, the prime duty, the first obedience, and the foremost sacrifice. Without faith God forfeits His glory, wisdom, truth, and mercy in us. The first duty of man is to believe in God and to honor Him with his faith. Faith is truly the height of wisdom, the right kind of righteousness, the only real religion. This will give us an idea of the excellence of faith. To believe in God as Abraham did is to be right with God because faith honors God. Faith says to God: "I believe what you say." When we pay attention to reason, God seems to propose impossible matters in the Christian Creed.” source