Thomas a Kempis emphasizes the importance of approaching the Sacrament with humility, faith, and reverence, urging believers to cleanse their conscience through true contrition and confession. He encourages deep reflection on one's sins, expressing sorrow for worldly desires, lack of discipline, and other faults, and calls for a firm commitment to daily improvement and spiritual growth. Kempis highlights the significance of offering oneself as a sacrifice to God, trusting in His care, and finding redemption and cleansing through the Sacrament of the Body of Christ, emphasizing God's desire for repentance and forgiveness.

THE VOICE OF CHRIST ABOVE all, God's priest should approach the celebration and reception of this Sacrament with the deepest humility of heart and suppliant reverence, with complete faith and the pious intention of giving honor to God. Carefully examine your conscience, then. Cleanse and purify it to the best of your power by true contrition and humble confession, that you may have no burden, know of no remorse, and thus be free to come near. Let the memory of all your sins grieve you, and especially lament and bewail your daily transgressions. Then if time permits, confess to God in the secret depths of your heart all the miseries your passions have caused. Lament and grieve because you are still so worldly, so carnal, so passionate and unmortified, so full of roving lust, so careless in guarding the external senses, so often occupied in many vain fancies, so inclined to exterior things and so heedless of what lies within, so prone to laughter and dissipation and so indisposed to sorrow and tears, so inclined to ease and the pleasures of the flesh and so cool to austerity and zeal, so curious to hear what is new and to see the beautiful and so slow to embrace humiliation and dejection, so covetous of abundance, so niggardly in giving and so tenacious in keeping, so inconsiderate in speech, so reluctant in silence, so undisciplined in character, so disordered in action, so greedy at meals, so deaf to the Word of God, so prompt to rest and so slow to labor, so awake to empty conversation, so sleepy in keeping sacred vigils and so eager to end them, so wandering in your attention, so careless in saying the office, so lukewarm in celebrating, so heartless in receiving, so quickly distracted, so seldom fully recollected, so quickly moved to anger, so apt to take offense at others, so prone to judge, so severe in condemning, so happy in prosperity and so weak in adversity, so often making good resolutions and carrying so few of them into action. When you have confessed and deplored these and other faults with sorrow and great displeasure because of your weakness, be firmly determined to amend your life day by day and to advance in goodness. Then, with complete resignation and with your entire will offer yourself upon the altar of your heart as an everlasting sacrifice to the honor of My name, by entrusting with faith both body and soul to My care, that thus you may be considered worthy to draw near and offer sacrifice to God and profitably receive the Sacrament of My Body. For there is no more worthy offering, no greater satisfaction for washing away sin than to offer yourself purely and entirely to God with the offering of the Body of Christ in Mass and Communion. If a man does what he can and is truly penitent, however often he comes to Me for grace and pardon, "As I live, saith the Lord God, I desire not the death of the wicked, but that the wicked turn from his way and live";[50] I will no longer remember his sins, but all will be forgiven him.