If one wished to obtain means for a profounder contemplation of the entrance of souls into divine things, not from the statements of that very insignificant sect from which he quoted, but from books— partly those of the Jews, which are read in their synagogues, and adopted by Christians, and partly from those of Christians alone— let him peruse, at the end of Ezekiel's prophecies, the visions beheld by the prophet, in which gates of different kinds are enumerated, which obscurely refer to the different modes in which divine souls enter into a better world; and let him peruse also, from the Apocalypse of John, what is related of the city of God, the heavenly Jerusalem, and of its foundations and gates. And if he is capable of finding out also the road, which is indicated by symbols, of those who will march on to divine things, let him read the book of Moses entitled Numbers, and let him seek the help of one who is capable of initiating him into the meaning of the narratives concerning the encampments of the children of Israel; viz., of what sort those were which were arranged towards the east, as was the case with the first; and what those towards the south-west and south; and what towards the sea; and what the last were, which were stationed towards the north. For he will see that there is in the respective places a meaning not to be lightly treated, nor, as Celsus imagines, such as calls only for silly and servile listeners: but he will distinguish in the encampments certain things relating to the numbers that are enumerated, and which are specially adapted to each tribe, of which the present does not appear to us to be the proper time to speak. Let Celsus know, moreover, as well as those who read his book, that in no part of the genuine and divinely accredited Scriptures are “seven” heavens mentioned; neither do our prophets, nor the apostles of Jesus, nor the Son of God Himself, repeat anything which they borrowed from the Persians or the Cabiri.
Source: Against Celsus (New Advent)