Yes the Incarnation is the ultimate revelation of God as He wanted us to perceive Him (with our limited senses). That is the "core" belief of Christianity, FK. God is ineffable, invisible Spirit who is nothing like us and whom we can neither know nor relate to. Christ, on the other hand, is both visible and comprehensible, a Person we can relate to, imitate and follow (in His humanity). That's why we can only come to God through Him, through His humanity.
Indwelling Spirit is, I believe, something St. Paul introduced. If He means that the love of God is in our hearts and minds, and that we imitate God in our spirit, I can agree with that concept but I think your side has something else in mind, more like an alien presence that was implanted in the "elect."
You yourself have pointed out that there are several passages in the Gospels in which there could have been no other direct witnesses, such as His trials in the desert and when He prayed to take the cup away. Yet, (I hope :) you accept those as true
I believe in the message of the Gospels, as I do in the message of the whole Bible when the message is Christ-like. As far as His trials in the desert is concerned, the Gospels, if I remember correctly, do not agree as to just when did He go to the desert (i.e. right after the Baptism, which is in an of itself strange), or after several days. So, there is some room for doubt.
Clearly, the Gospels could not be eyewitnesses to everything there is in them. They are narratives which in most places corroborate themselves. In other places, the accounts differ or are even not mentioned (for instance John doesn't even talk about the trial of Jesus by the Sanhedrin! In other places the same conversation takes on a life of its own, such as the alleged exchange between Christ and Pontius Pilate, what Jesus said on the Cross, or how many women discovered the empty tomb, how many angels were there, etc., etc., etc.)
I think you are concentrating on the the stories more than on the message behind them. The essence of Christ's teachings is fundamentally different from the angry messages of other Jewish "messiahs," including St. John the Forerunner/Baptist. He was as unlike the Jewish warrior-king as it gets.
The second problem is that at least two our of four Gospel writers are not eyewitnesses (Mark and Luke), and at most that all four were not the Apostoles to whom the Gospels are attributed. However, the message is a compilation of what is probably part legend and part eyewitness account of Jesus' ministry which the mainline Christians accepted and lived by in the 1st century A.D.
The scriptures are authenticated by GOD, , not by how many humans were around to vouch for them.
Every other religion says that for their holy books. That's about as convincing as saying "it must be true, it's in the New York Times," FK. You must already believe that in oder for that to be true, so no matter how you look at it, a believing human is always vouching for them being true.
So then I would assume that you think the Biblical account of Pentecost is all myth? For example:
Acts 2:1-4 : 1 When the day of Pentecost came, they were all together in one place. 2 Suddenly a sound like the blowing of a violent wind came from heaven and filled the whole house where they were sitting. 3 They saw what seemed to be tongues of fire that separated and came to rest on each of them. 4 All of them were filled with the Holy Spirit and began to speak in other tongues as the Spirit enabled them. ................
Acts 2:31-33 : 31 Seeing what was ahead, he [David] spoke of the resurrection of the Christ, that he was not abandoned to the grave, nor did his body see decay. 32 God has raised this Jesus to life, and we are all witnesses of the fact. 33 Exalted to the right hand of God, he has received from the Father the promised Holy Spirit and has poured out what you now see and hear. ................
Acts 2:38-39 : 38 Peter replied, "Repent and be baptized, every one of you, in the name of Jesus Christ for the forgiveness of your sins. And you will receive the gift of the Holy Spirit. 39 The promise is for you and your children and for all who are far off — for all whom the Lord our God will call."
Is it correct then that you accept the first part of verse 38, but reject the second part? If so, that's pretty selective I think. :) If Paul introduced the Holy Spirit then He surely is not from God, He would be an invention of Paul's. That tells me you don't believe it as the Bible tells it. Hypothetically, if the Bible turned out to be right and it was something like an "alien presence", like you said, may I assume that you would reject this presence since it is alien to you?
I think you are concentrating on the the stories more than on the message behind them.
I just think that when one throws out the history behind the stories the message itself is ruined. Myths can be and are interpreted in a multitude of ways. It's whatever the reader wants it to mean since it never really happened. Inconvenient elements of the story can be dropped without penalty (it's not part of the message) and new elements can be added in to taste. That is faith a la carte, and with all respect that's what I see you doing when you dismiss the God of the OT.
The essence of Christ's teachings is fundamentally different from the angry messages of other Jewish "messiahs," including St. John the Forerunner/Baptist. He was as unlike the Jewish warrior-king as it gets.
Not only did John the Baptist specifically deny being the Messiah, but Jesus Himself said that no finer person (excluding Himself) has ever walked the earth. So, I would assume you might think those passages never happened either? If the message of Jesus was fundamentally different from John the Baptist's would not Jesus have condemned it, at least in His heart?