Holy Communion is the very Body and Blood of Christ, and the Church approaches it with care. Preparation is not to earn what can only be given, but to open the heart to receive it worthily: the prayers before Communion, a period of fasting, and, as one's priest directs, the mystery of Confession, so that one comes to the Cup reconciled.
The prayers before Communion are among the most beautiful the Church possesses, the confession of faith in the true presence, the acknowledgment of one's unworthiness, and the plea that the Gifts be received not to judgment but to healing. St John Chrysostom's prayer, “I believe, O Lord, and I confess,” is prayed by the faithful in the hours before approaching.
After receiving, the Church gives thanks. The prayers of thanksgiving after Communion keep the gift from being forgotten in the rush of the day, asking that Christ, now dwelling within, remain and transform. Preparation, reception, thanksgiving, the whole of it is the Church teaching us how to be given the greatest of gifts.