The heart is naturally hard, and grows harder by custom in sin, especially by long abuse of mercy, neglect of the means of grace, and resisteing the spirit of grace.
This life was not intended to be the place of our perfection, but the preparation for it.
Suffering so unbolts the door of the heart, that the Word hath easier entrance.
The longer you delay, the more your sin gets strength and rooting. If you cannot bend a twig, how will you be able to bend it when it is a tree?