Jesus had made these revelations to His disciples while abiding with them, but when the Holy Spirit came to abide in them, the Spirit would enable them to understand them. [source][source][source]
Jesus now identified the Helper whom He had promised earlier as the Holy Spirit (cf. John 14:16-17). He is the Spirit characterized by holiness as well as by truth ( John 14:17). [source][source][source]
The Father would send the Holy Spirit in Jesus" name (i.e, as Jesus" emissary and with exactly the same attitude toward God"s will that Jesus had). The Son had come as the Father"s emissary, and now the Spirit was about to come as the Son"s emissary. [source][source][source]
The Spirit would teach them all things, which in the context refers to all things that were presently obscure, about which the various disciples kept raising questions ( John 13:36; John 14:5; John 14:8; John 14:22). He would do this partially by bringing to their memories things that Jesus had said that would become clear in the light of His "glorification" (cf. John 2:19-22; John 12:16; John 20:9). [source][source][source]
Notice that the particular ministry of the Spirit that is in view is teaching. The illumination that Jesus promised here was specifically to the Eleven and their contemporaries. It was a promise to those who had heard His teaching before the Cross but did not understand it until after the Resurrection. However this promise did not find complete fulfillment in the apostolic age. The Holy Spirit continues His teaching ministry today by enlightening disciples as they study Jesus" teachings. In this sense the Holy Spirit is the true teacher of every Christian, and human teachers serve a secondary role (cf. 1 John 2:27). The role of the Scriptures in the process is fundamental since they contain all that Jesus personally taught and approved. [source][source][source]