E01136: Augustine of Hippo, in his City of God (22.9), explains that the miracles performed at the relics of martyrs are witness to the resurrection of Christ. All the miracles are performed by God's power, only God is the object of Christian worship, and the veneration of martyrs does not resemble the cult of pagan gods and heroes. Written in Latin in Hippo Regius (North Africa), c. 426/427.

Augustine, City of God 22.9

Cui, nisi huic fidei adtestantur ista miracula, in qua praedicatur Christus resurrexisse in carne et in caelum ascendisse cum carne? Quia et ipsi martyres huius fidei martyres, id est huius fidei testes, fuerunt; huic fidei testimonium perhibentes mundum inimicissimum et crudelissimum pertulerunt eum que non repugnando, sed moriendo uicerunt; pro ista fide mortui sunt, qui haec a domino inpetrare possunt, propter cuius nomen occisi sunt; pro hac fide praecessit eorum mira patientia, ut in his miraculis tanta ista potentia sequeretur. Nam si carnis in aeternum resurrectio uel non praeuenit in Christo uel non uentura est, sicut praenuntiatur a christo uel sicut praenuntiata est a prophetis, a quibus praenuntiatus est Christus: cur et mortui tanta possunt, qui pro ea fide, qua haec resurrectio praedicatur, occisi sunt? Siue enim deus ipse per se ipsum miro modo, quo res temporales operatur aeternus, siue per suos ministros ista faciat; et eadem ipsa, quae per ministros facit, siue quaedam faciat etiam per martyrum spiritus, sicut per homines adhuc in corpore constitutos, siue omnia ista per angelos, quibus inuisibiliter, incorporaliter, inmutabiliter imperat, operetur, ut, quae per martyres fieri dicuntur, eis orantibus tantum et inpetrantibus, non etiam operantibus fiant; siue alia istis, alia illis modis, qui nullo modo conprehendi a mortalibus possunt: ei tamen adtestantur haec fidei, in qua carnis in aeternum resurrectio praedicatur. Hic forte dicturi sunt etiam deos suos aliqua mira fecisse. Bene, si iam incipiunt deos suos nostris mortuis hominibus comparare. An dicent etiam se habere deos ex hominibus mortuis, sicut Herculem, sicut Romulum, sicut alios multos, quos in deorum numerum receptos opinantur? Sed nobis martyres non sunt dii, quia unum eundem que deum et nostrum scimus et martyrum. Nec tamen miraculis, quae per memorias nostrorum martyrum fiunt, ullo modo sunt comparanda miracula, quae facta per templa perhibentur illorum. Verum si qua similia uidentur, sicut a moyse magi pharaonis, sic eorum dii uicti sunt a martyribus nostris. Fecerunt autem illa daemones eo fastu inpurae superbiae, quo eorum dii esse uoluerunt; faciunt autem ista martyres uel potius deus aut cooperantibus aut orantibus eis, ut fides illa proficiat, qua eos non deos nostros esse, sed unum deum nobis cum habere credamus. Denique illi talibus diis suis et templa aedificauerunt et statuerunt aras, et sacerdotes instituerunt et sacrificia fecerunt; nos autem martyribus nostris non templa sicut diis, sed memorias sicut hominibus mortuis, quorum apud deum uiuunt spiritus, fabricamus; nec ibi erigimus altaria, in quibus sacrificemus martyribus, sed uni deo et martyrum et nostro; ad quod sacrificium sicut homines dei, qui mundum in eius confessione uicerunt, suo loco et ordine nominantur, non tamen a sacerdote, qui sacrificat, inuocantur. Deo quippe, non ipsis sacrificat, quamuis in memoria sacrificet eorum, quia dei sacerdos est, non illorum. Ipsum uero sacrificium corpus est christi, quod non offertur ipsis, quia hoc sunt et ipsi. Quibus igitur potius credendum est miracula facientibus? eis ne qui se ipsos uolunt haberi deos ab his quibus ea faciunt, an eis qui, ut in deum credatur, quod et Christus est, faciunt quidquid mirabile faciunt? Eis ne qui sacra sua etiam crimina sua esse uoluerunt, an eis qui nec laudes suas uolunt esse sacra sua, sed totum, quod ueraciter laudantur, ad eius gloriam proficere in quo laudantur? In domino quippe laudantur animae eorum. Credamus ergo eis et uera dicentibus et mira facientibus. Dicendo enim uera passi sunt, ut possint facere mira. In eis ueris est praecipuum, quod christus resurrexit a mortuis et inmortalitatem resurrectionis in sua carne primus ostendit, quam nobis adfuturam uel in principio noui saeculi uel in huius fine promisit.
 

'To what do these miracles witness, but to this faith which preaches Christ risen in the flesh, and ascended with the same into heaven? For the martyrs themselves were martyrs, that is to say, witnesses of this faith, drawing upon themselves by their testimony the hatred of the world, and conquering the world not by resisting it, but by dying. For this faith they died, and can now ask these benefits from the Lord in whose name they were slain. For this faith their marvellous constancy was exercised, so that in these miracles great power was manifested as the result. For if the resurrection of the flesh to eternal life had not taken place in Christ, and were not to be accomplished in His people, as predicted by Christ, or by the prophets who foretold that Christ was to come, why do the martyrs who were slain for this faith which proclaims the resurrection possess such power? For whether God Himself wrought these miracles by that wonderful manner of working by which, though Himself eternal, He produces effects in time; or whether He wrought them by servants, and if so, whether He made use of the spirits of martyrs as He uses men who are still in the body, or effects all these marvels by means of angels, over whom He exerts an invisible, immutable, incorporeal sway, so that what is said to be done by the martyrs is done not by their operation, but only by their prayer and request; or whether, finally, some things are done in one way, others in another, and so that man cannot at all comprehend them,—nevertheless these miracles attest this faith which preaches the resurrection of the flesh to eternal life.

Here perhaps our adversaries will say that their gods also have done some wonderful things, if now they begin to compare their gods to our dead men. Or will they also say that they have gods taken from among dead men, such as Hercules, Romulus, and many others whom they fancy to have been received into the number of the gods? But our martyrs are not our gods; for we know that the martyrs and we have both but one God, and that the same. Nor yet are the miracles which they maintain to have been done by means of their temples at all comparable to those which are done by the tombs of our martyrs. If they seem similar, their gods have been defeated by our martyrs as Pharaoh's magi were by Moses. In reality, the demons wrought these marvels with the same impure pride with which they aspired to be the gods of the nations; but the martyrs do these wonders, or rather God does them while they pray and assist, in order that an impulse may be given to the faith by which we believe that they are not our gods, but have, together with ourselves, one God. In fine, they built temples to these gods of theirs, and set up altars, and ordained priests, and appointed sacrifices; but to our martyrs we build, not temples as if they were gods, but monuments as to dead men whose spirits live with God. Neither do we erect altars at these monuments that we may sacrifice to the martyrs, but to the one God of the martyrs and of ourselves; and in this sacrifice they are named in their own place and rank as men of God who conquered the world by confessing Him, but they are not invoked by the sacrificing priest. For it is to God, not to them, he sacrifices, though he sacrifices at their monument; for he is God's priest, not theirs. The sacrifice itself, too, is the body of Christ, which is not offered to them, because they themselves are this body. Which then can more readily be believed to work miracles? They who wish themselves to be reckoned gods by those on whom they work miracles, or those whose sole object in working any miracle is to induce faith in God, and in Christ also as God? They who wished to turn even their crimes into sacred rites, or those who are unwilling that even their own praises be consecrated, and seek that everything for which they are justly praised be ascribed to the glory of Him in whom they are praised? For in the Lord their souls are praised. Let us therefore believe those who both speak the truth and work wonders. For by speaking the truth they suffered, and so won the power of working wonders. And the leading truth they professed is that Christ rose from the dead, and first showed in His own flesh the immortality of the resurrection which He promised should be ours, either in the beginning of the world to come, or in the end of this world.'

Text: Dombart and Kalb 1955. Translation: Dods 1887 (slightly changed).