Thomas Watson, Religion Our True Interest (1682), reprinted as The Great Gain of Godliness (2006), p. 92:
Get a love for God and his ways. One cannot but think of that which he loves: 'Can a maid forget her ornament?' (Jer. 2:32). When she has not her jewel on her ear, she will have it her thoughts. A person deeply in love cannot keep his thoughts off from the object he loves. The reason we think on God no more, is because we love him no more. Let there be but one spark of love to God and it will fly upward in heavenly thoughts and prayers. By nature we have quicksilver hearts which cannot be made to fix on God, but by love.