Because spiritual things are AGAINST nature. Everything in piety is opposite to nature. There are two things in true religion, and both are against nature.
(1.) Matters of faith. As, for men to be justified by the righteousness of another, to become a fool that he may be wise, to save all by losing all—this is against nature.
(2.) Matters of practice. As, self-denial. As for a man to deny his own wisdom, and see himself blind. As to have his own will, and have it melted into the will of God. As to be plucking out the right eye, beheading and crucifying that sin which is the favorite, and lies nearest to the heart. As for a man to be dead to the world, and in the midst of need to abound. As for him to take up the cross, and follow Christ, not only in golden-but in bloody paths. As to embrace religion, when it is dressed in rags, and all the jewels of honor and pre- ferment are pulled off. All this is against nature and therefore must be learned.
Thomas Watson. The Art of Divine Contentment.
