John Murray, Principles of Conduct, Eerdmans, 1978, p. 230.
Devotion signifies a life given, or devoted to God. He therefore is the devout (godly) man, who lives no longer to his own will, or the way and spirit of the world, but to the sole will of God, who considers God in everything, who makes all the parts of his common life, parts of piety (godliness), by doing everything in the name of God, and under such rules as are conformable to His Glory.
John Murray, Principles of Conduct, Eerdmans, 1978, p. 230.