When I grant you the grace of devotion, give thanks to God, not because you deserve to enjoy it, but because I have had mercy on you. And if you feel no devotion, but suffer dryness of soul, persevere in prayer, sigh, and knock (Matt. 7: 7; Luke 11: 9); persist until you merit to receive some crumb or drop of saving grace. You have need of Me; I have no need of you (2 Macc 14: 35.). You do not come to sanctify Me, but I come to sanctify and raise you. You come in order to be hallowed and united to Me; that you may receive fresh grace, and be inspired anew to amendment of life. Do not neglect this grace (I Tim 4: 14), but prepare yourself with all care, and invite your Beloved into your heart.

Not only must you make a devout preparation before Holy Communion, but also carefully foster your devotion after receiving the Sacrament. No less vigilance is required after Communion than devout preparation beforehand. For a constant vigilance after Communion is the best preparation for receiving richer graces; and a man will be entirely undisposed to do this if he straightway turns to outward pleasures. Beware of much talk (Prov 10: 19.): remain in some quiet place, and savour the presence of God; for you possess Him whom the whole world cannot take away from you. I am He to whom you should offer your whole self, that, set free from care, you may no longer live in yourself, but in Me (John15: 4: Gal 2:20).

Words of Christ, from The Imitation of Christ
Thomas A Kempis