There is no logical reason to think that John 14, 15 and 16 were referring to anything other than the promised Holy Spirit which came at Pentecost.
Logic tells us, when I compare verses, that the Holy Spirit is the Advocate whom Jesus promised to His disciples to teach them and remind them what Jesus had said to them.
John 14:25 “All this I have spoken while still with you. 26 But the Advocate, the Holy Spirit, whom the Father will send in my name, will teach you all things and will remind you of everything I have said to you.
Then we see that the Advocate is the Spirit of Truth whom Jesus sends to His disciples.
John 15:26 “When the Advocate comes, whom I will send
to you from the Father—the Spirit of truth who goes out from the Father—he will testify about me. 27 And you also must testify, for you have been with me from the beginning.
Then we can see again that the Spirit of Truth is promised to Jesus disciples, to guide them into all the truth.
John 16:12 “I have much more to say to you, more than you can now bear. 13 But when he, the Spirit of truth, comes, he will guide
you into all the truth. He will not speak on his own; he will speak only what he hears, and he
will tell you what is yet to come.
Here again the Spirit of Truth is promised to Jesus disciples and He said it lives with them and will be in them.
John 14:16And I will ask the Father, and He will give you another Advocate to be with you forever— 17
the Spirit of truth. The world cannot receive Him, because it neither sees Him nor knows Him. But you do know Him, for He abides with you and will be in you.
The promise was never
a once and for all time promise. The promise was for all Christians.
So you quote the same verses that I have quoted and cannot see what they tell us.
Then when you quote the prophecy of Joel you do not quote what Peter said about it. He was telling to people that he and his Spirit filled friends were not drunk but that it was the fulfilment of part of the prophecy of Joel,,,,,,,,,,, and the he quoted the prophecy.
Acts 2:12 And all were amazed and perplexed, saying to one another, “What does this mean?” 13 But others mocking said, “They are filled with new wine.”
Peter’s Sermon at Pentecost
14 But Peter, standing with the eleven, lifted up his voice and addressed them: “Men of Judea and all who dwell in Jerusalem, let this be known to you, and give ear to my words. 15
For these people are not drunk, as you suppose, since it is only the third hour of the day. 16 But this is what was uttered through the prophet Joel:
17 “ ‘And in the last days it shall be, God declares,
that I will pour out my Spirit on all flesh,
and your sons and your daughters shall prophesy,
and your young men shall see visions,
and your old men shall dream dreams;
18 even on my male servants and female servants
in those days I will pour out my Spirit, and they shall prophesy.
19 And I will show wonders in the heavens above
and signs on the earth below,
blood, and fire, and vapor of smoke;
20 the sun shall be turned to darkness
and the moon to blood,
before the day of the Lord comes, the great and magnificent day.
21 And it shall come to pass that
ceveryone who calls upon the name of the Lord shall be saved.’
You want the time of Baha'u'llah to be the last days but the Bible indicates that the last days started with Jesus and end when Jesus returns. For a start we read the above prophecy of Joel and that it would happen in the last days.
Other passages in the New Testament also tell us that the last days started in Jesus day, as this quote from this site tells us. Denying it is no more than showing the fruit of the false prophet and denying that the Bible is speaking the truth.
www.preceptaustin.org
“In these last days He [God] has spoken [finally, once for all] to us by his Son” (Heb. 1:2), and “He was chosen before the creation of the world, but was revealed in these last times for your sake” (1 Pet. 1:20).
Broadly speaking, therefore, the last days include the earthly life and ministry of Jesus Christ, the entire history of the church to the present, as well as all events prophesied in the Scriptures that are still unfulfilled. Even near the beginning of the church's history John pointed out that the “many antichrists [who] have come” are evidence that this “is the last hour” (1 John 2:18).
So you like to quote passages that show us that Baha'u'llah is not the return of Christ and even highlight parts that show us that. OK thanks for that.