The more a true saint loves God with a gracious love, the more he desires to love him, and the more uneasy is he at his want of love to him; the more he hates sin, the more he desires to hate it, and laments that he has so much remaining love to it; the more he mourns for sin, the more he longs to mourn; the more his heart is broken, the more he desires it should be broke: the more he thirsts and longs after God and holiness, the more he longs to long, and breathe out his very soul in longings after God. The kindling and raising of gracious affections is like kindling a flame; the higher it is raised, the more ardent it is; and the more it burns, the more vehemently does it tend and seek to burn.
Jonathan Edwards, The Religious Affections (pg.303).
He who has no religious affection is in a state of spiritual death, and is wholly destitute of the powerful, quickening, saving influences of the Spirit of God upon his heart. As there is no true religion where there is nothing else but affection, so there is no true religion where there is no religious affection…If the great things of religion are rightly understood, they will affect the heart. The reason why men are not affected by such infinitely great, important, glorious, and wonderful things, as they often hear and read of in the Word of God, is, undoubtedly, because they are blind; if they were not so, it would be impossible, and utterly inconsistent with human nature, that their hearts should be otherwise than strongly impressed, and greatly moved by such things.
Jonathan Edwards, The Religious Affections (pgs. 49-50)