Quote from : Johann Arndt: True Christianity Book

By daily contrition, and habitual mortification of the flesh, man is day by day RENEWED, bearing heavenly fruits and celestial graces, of an inexplicable sweetness. Contrariwise, the pleasure of the world bringeth heaviness of heart, vexation of spirit, and a wounded conscience: yea, so great hence is the calamity of the soul, and so heavy the loss of the heavenly gift (a loss which necessarily flows from the pleasures of the flesh, and from worldly delights) that he who duly calls the same to mind, cannot be exceedingly fear and dread any of the fleshly and worldly joys, which serve but to divert him from those that are spiritual and heavenly, and to quench in him the most sweet grace of devotion that brings the soul into the kingdom of God.