Devotion signifies a life given, or devoted to God

He therefore is the devout 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 serves God in everything, who makes all the parts of his common life, parts of piety, by doing everything in the name of God, and under such rules as are conformable to his Glory.

—William Law
The Works of the Reverend William Law (London: J. Richardson, 1762), 4:7.