Because they write amazing stuff like this:
I would not [lack] the sweet experience of the consolations of God for all the bitterness of affliction; nay, whether God come to his children with a rod or a crown, if he come himself with it, it is well. Welcome, welcome Jesus, what way soever thou come, if we can get a sight of thee. And sure I am, it is better to be sick, providing Christ come to the bed-side, and draw aside the curtains, and say, ‘Courage, I am they salvation’, than to enjoy health, being lusty and strong, and never to be visited of God. -Samuel Rutherford.