Cyprian of Carthage, Epistle 63.2 (Cup of the Lord)
Since the Lord threatens such torments and punishments on the day of judgment to those who obey the devil and sacrifice to idols, how can anyone who has obeyed and served the devil's priests imagine he can function as God's priest? Or how can he suppose his hand can be transferred to God's sacrifice and the Lord's prayer when that prayer has been taken captive by sacrilege and crime? The divine Scriptures forbid priests from approaching the sacrifice even when guilty of a lesser offense. Leviticus says: 'A man in whom there is a defect and a stain shall not approach to offer gifts to God.' Exodus says: 'The priests who approach the Lord God shall sanctify themselves, lest the Lord abandon them.' And again: 'When they approach to minister at the holy altar, they shall not bring sin upon themselves, lest they die.' Therefore, those who have brought grave sins upon themselves — that is, who have made sacrilegious sacrifices by sacrificing to idols — cannot claim God's priesthood for themselves, nor can they offer any prayer in His sight for their brothers. For it is written in the Gospel: 'God does not hear the sinner; but if anyone worships God and does His will, He hears him.' (Leviticus; Exodus; Gospel) Although the deep darkness of approaching shadows has so blinded the hearts of some that they admit no light concerning the wholesome precepts, they have turned away from the right boundary of the true path and are swept headlong down the precipice and sheer drop of their crimes, through night and error.
Latin
Cum ergo haec tormenta, haec supplicia in die judicii Dominus comminetur iis qui diabolo obtemperant et idolis sacrificant, quomodo se putat posse agere pro Dei sacerdote qui obtemperavit et servivit diaboli sacerdotibus? aut quomodo putat manum suam transferri posse ad Dei sacrificium et precem Domini quae captiva fuerit sacrilegio et crimini, quando in Scripturis divinis Deus ad sacrificium prohibeat accedere sacerdotes etiam in leviori crimine constitutos, et in Levitico dicat: Homo in quo fuerit vitium et macula non accedet offerre dona Deo. Item in Exodo: Et sacerdotes qui accedunt ad Dominum Deum sanctificentur, ne forte derelinquat illos Dominus. Et iterum: Et cum accedunt ministrare ad altare sancti, non adducent in se delictum, ne moriantur. Qui ergo gravia in se delicta adduxerunt, id est, qui idolis sacrificando sacrilega sacrificia fecerunt, sacerdotium Dei sibi vindicare non possunt, nec ullam in conspectu ejus precem pro fratribus facere, quando in Evangelio scriptum sit: Deus peccatorem non audit; sed si quis Deum coluerit et voluntatem ejus fecerit, illum audit. Quamvis sic quorumdam pectora tenebrarum ingruentium profunda caligo caecaverit, ut de praeceptis salubribus nihil lucis admittant, sed se mel a recto limite veri itineris aversi, per praeceps et per abruptum criminum suorum nocte atque errore rapiantur.