5 Would therefore, O my beloved, that as the word requires, we might here so govern ourselves at all times and entirely, and so live, as never to forget the noble acts of God, nor to depart from the practice of virtue! As also the Apostolic voice exhorts; 'Remember Jesus Christ, that He rose from the dead.' Not that any limited season of remembrance was appointed, for at all times He should be in our thoughts. But because of the slothfulness of many, we delay from day to day.
Let us then begin in these days. To this end a time of remembrance is permitted, that it may show forth to the saints the reward of their calling, and may exhort the careless while reproving them. Therefore in all the remaining days, let us persevere in virtuous conduct, repenting as is our duty, of all that we have neglected, whatever it may be; for there is no one free from defilement, though his course may have been but one hour on the earth, as Job, that man of surpassing fortitude, testifies.
But, 'stretching forth to those things that are to come,' let us pray that we may not eat the Passover unworthily, lest we be exposed to dangers. For to those who keep the feast in purity, the Passover is heavenly food; but to those who observe it profanely and contemptuously, it is a danger and reproach. For it is written, 'Whosoever shall eat and drink unworthily, is guilty of the death of our Lord.' Wherefore, let us not merely proceed to perform the festal rites, but let us be prepared to draw near to the divine Lamb, and to touch heavenly food.
Let us cleanse our hands, let us purify the body. Let us keep our whole mind from guile; not giving up ourselves to excess, and to lusts, but occupying ourselves entirely with our Lord, and with divine doctrines; so that, being altogether pure, we may be able to partake of the Word.
Source: Letters (New Advent)