Tertullian: On Purgatory and intercessory prayer

"THAT allegory of the Lord which is extremely clear and simple in its meaning, and ought to be from the first understood in its plain and natural sense...Then, again, should you be disposed to apply the term 'adversary' to the devil, you are advised by the (Lord's) injunction, while you are in the way with him, 'to make even with him such a compact as may be deemed compatible with the requirements of your true faith. Now the compact you have made respecting him is to renounce him, and his pomp, and his angels. Such is your agreement in this matter. Now the friendly understanding you will have to carry out must arise from your observance of the compact: you must never think of getting back any of the things which you have abjured, and have restored to him, lest he should summon you as a fraudulent man, and a transgressor of your agreement, before God the Judge (for in this light do we read of him, in another passage, as 'the accuser of the brethren,' or saints, where reference is made to the actual practice of legal prosecution); and lest this Judge deliver you over to the angel who is to execute the sentence, and he commit you to the prison of hell, out of which there will be no dismissal until the smallest even of your delinquencies be paid off in the period before the resurrection. What can be a more fitting sense than this? What a truer interpretation?" (A Treatise on the Soul, 35) 

"ALL souls, therefore; are shut up within Hades: do you admit this? It is true, whether you say yes or no: moreover, there are already experienced there punishments and consolations; and there you have a poor man and a rich...Moreover, the soul executes not all its operations with the ministration of the flesh; for the judgment of God pursues even simple cogitations and the merest volitions. 'Whosoever looketh on a woman to lust after her, hath committed adultery with her already in his heart.' Therefore, even for this cause it is most fitting that the soul, without at all waiting for the flesh, should be punished for what it has done without the partnership of the flesh. So, on the same principle, in return for the pious and kindly thoughts in which it shared not the help of the flesh, shall it without the flesh receive its consolation. In short, inasmuch as we understand 'the prison' pointed out in the Gospel to be Hades, and as we also interpret 'the uttermost farthing' to mean the very smallest offence which has to be recompensed there before the resurrection, no one will hesitate to believe that the soul undergoes in Hades some compensatory discipline, without prejudice to the full process of the resurrection, when the recompense will be administered through the flesh besides." (A Treatise on the Soul, 58)

"AS often as the anniversary comes round, we make offerings for the dead as birthday honours." (The Chaplut, 3)

"A woman is more bound when her husband is dead...Indeed, she prays for his soul, and requests refreshment for him meanwhile, and fellowship (with him) in the first resurrection; and she offers (her sacrifice) on the anniversary of his falling asleep." (On Monogamy, 10)

~Tertullian

Woodcut depicting Quintus Septimius Florens Tertullianus