Seeing, however, that Celsus alleges that “Christians are won over by us through vain hopes,” we thus reply to him when he finds fault with our doctrine of the blessed life, and of communion with God: As for you, good sir, they also are won over by vain hopes who have accepted the doctrine of Pythagoras and Plato regarding the soul, that it is its nature to ascend to the vault of heaven, and in the super-celestial space to behold the sights which are seen by the blessed spectators above.
According to you, O Celsus, they also who have accepted the doctrine of the duration of the soul (after death), and who lead a life through which they become heroes, and make their abodes with the gods, are won over by vain hopes. Probably also they who are persuaded that the soul comes (into the body) from without, and that it will be withdrawn from the power of death, would be said by Celsus to be won over by empty hopes. Let him then come forth to the contest, no longer concealing the sect to which he belongs, but confessing himself to be an Epicurean, and let him meet the arguments, which are not lightly advanced among Greeks and Barbarians, regarding the immortality of the soul, or its duration (after death), or the immortality of the thinking principle; and let him prove that these are words which deceive with empty hopes those who give their assent to them; but that the adherents of his philosophical system are pure from empty hopes, and that they indeed lead to hopes of good, or— what is more in keeping with his opinions— give birth to no hope at all, on account of the immediate and complete destruction of the soul (after death). Unless, perhaps, Celsus and the Epicureans will deny that it is a vain hope which they entertain regarding their end—pleasure—which, according to them, is the supreme good, and which consists in the permanent health of the body, and the hope regarding it which is entertained by Epicurus.
Source: Against Celsus (New Advent)