26 And when you have thus wrestled against the Jews—when you have worsted them by parallel instances, then come further to the pre-eminence of the Saviour's glory; namely, that they were the servants, but He the Son of God. And thus you will be reminded of His pre-eminence, by the thought that a servant of Christ was caught up to the third heaven. For if Elias attained as far as the first heaven, but Paul as far as the third, the latter, therefore, has obtained a more honourable dignity.
Be not ashamed of your Apostles; they are not inferior to Moses, nor second to the Prophets; but they are noble among the noble, yea, nobler still. For Elias truly was taken up into heaven; but Peter has the keys of the kingdom of heaven, having received the words, Whatsoever you shall loose on earth shall be loosed in heaven. Elias was taken up only to heaven; but Paul both into heaven, and into paradise (for it behooved the disciples of Jesus to receive more manifold grace), and heard unspeakable words, which it is not lawful for man to utter.
But Paul came down again from above, not because he was unworthy to abide in the third heaven, but in order that after having enjoyed things above man's reach, and descended in honour, and having preached Christ, and died for His sake, he might receive also the crown of martyrdom. But I pass over the other parts of this argument, of which I spoke yesterday in the Lord's-day congregation; for with understanding hearers, a mere reminder is sufficient for instruction.
Source: Catechetical Lectures (New Advent)