15 Moreover, beloved brethren, a new kind of devastation has appeared; and, as if the storm of persecution had raged too little, there has been added to the heap, under the title of mercy, a deceiving mischief and a fair-seeming calamity. Contrary to the vigour of the Gospel, contrary to the law of the Lord and God, by the temerity of some, communion is relaxed to heedless persons—a vain and false peace, dangerous to those who grant it, and likely to avail nothing to those who receive it.
They do not seek for the patience necessary to health nor the true medicine derived from atonement. Penitence is driven forth from their breasts, and the memory of their very grave and extreme sin is taken away. The wounds of the dying are covered over, and the deadly blow that is planted in the deep and secret entrails is concealed by a dissimulated suffering. Returning from the altars of the devil, they draw near to the holy place of the Lord, with hands filthy and reeking with smell, still almost breathing of the plague-bearing idol-meats; and even with jaws still exhaling their crime, and reeking with the fatal contact, they intrude on the body of the Lord, although the sacred Scripture stands in their way, and cries, saying, “Every one that is clean shall eat of the flesh; and whatever soul eats of the flesh of the saving sacrifice, which is the Lord's, having his uncleanness upon him, that soul shall be cut off from his people.” Also, the apostle testifies, and says, “You cannot drink the cup of the Lord and the cup of devils; you cannot be partakers of the Lord's table and of the table of devils.” He threatens, moreover, the stubborn and froward, and denounces them, saying, “Whosoever eats the bread or drinks the cup of the Lord unworthily, is guilty of the body and blood of the Lord.”
Source: The Treatises of Cyprian (New Advent)