Insights from the Ascension of Isaiah
The Ascension of Isaiah is an early Christian document that is thought to have been written some time in the second century A.D., and is considered a Christian re-working of an older Jewish tradition. It resembles, in some ways, Isaiah 6, but details a much more elaborate vision, in which Isaiah is taken, in spirit, through the various levels of Heaven until he reaches the highest heaven, where he is privileged to behold a vision of the Father, Beloved Son, and Holy Spirit.
For further background info on Ascension of Isaiah, and to read the text (translated from the Greek version), please see http://www.earlychristianwritings.com/ascension.html.
Starting in Chapter 6 of the text, Isaiah recounts the vision that he saw in which a glorious angel comes to him, takes him by the hand, and leads him upwards into the heavens. The angel declares the purpose of this celestial journey:
When I have raised thee on high through the various degrees…You will see one who is greater than I…and his Father also who is greater you will see (vv. 7:4, 7-8).