for the law of God must always have its operation and strength, which the law of man has not.
 Martin Luther, Table Talk (1566). copy citation

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Author Martin Luther
Source Table Talk
Topic strength God
Date 1566
Language English
Reference
Note Translated by William Hazlitt
Weblink http://www.ntslibrary.com/PDF%20Books/Luther%20Table%20Talk.pdf

Context

“I have sinned against God, and have offended. Then the law has well and rightly finished its work and office. After these came a third, and said: `tis one matter to be simply a law, and another to be God’s law; for the law of God must always have its operation and strength, which the law of man has not. To him I made this answer: The law must be distinguished, understood, and divided three-fold: first, a written law, second, a verbal, third, a spiritual law. The written law, which is written in the book, is like a block, which, without motion, remains lying;” source