There are two things, which I have always looked upon as difficult. The one is, to make the wicked sad; the other is, to make the godly joyful.
Sorrow in the godly comes from a double spring: either because their inward comforts are darkened, or their outward comforts are disturbed. To cure both these troubles… I would prescribe them to take, now and then, a little of this medicine: all things work together for good to them that love God.
To know that nothing hurts the godly, is a matter of comfort; but to be assured that all things which fall out shall co operate for their good, that their crosses shall be turned into blessings, that showers of affliction water the withering root of their grace and make it flourish more; this may fill their hearts with joy till they run over.
Taken from the preface of All Things for Good. You can see/purchase Watson’s other amazing books here.