I thank you for posting that.
John 5:6-12 gets it clear the connection between
the truth, the life, the way, the witness, the spirit
And when you go back to the Genesis, when God says about "if you eat from the fruit you SHALL SURELLY DIE".
In many verses, when God talks about life, he is talkinga about that component of connection to him, and the spirit.
It is taught with certain logic as to be scientific, metaphysic law, but with simple terms we could understand.
So when we got the Saviour, the Christ, the first time, the mechanics of salvation/universe got translated into believing in him, his sacrifice, his water, his spirit and his blood.
The fountain of living waters you just quoted. Matches the "Im the truth, the way and the life".
It is repeated over and over in similar ways, through different terminology across the whole Bible.
Whenever God talks about life, its about this.
When they want to talk about what we were taught to understand as life and death, they use "asleep/sleep". You are not alive when you are born of water, or water and blood, but water, blood and spirit. Thats why the baptism in water. Or the reason to be "reborn in Jesus Christ".
There is a reason for all that.
"He that hath the Son hath life, and he that hath not the Son of God hath not life."
Wich is believing (and keeping all the commandments and not sinning, And loving one another). And then he talks about the witness as the one who believes on the Son of God. And calls a liar whoever doesnt believes. So the wording "witness" could be synonimous/paralel of "truth".
Relates Spirit with witness. Witness as opposed of liar. And then "Spirit is truth".
And it also related spirit, water and blood. "even Jesus Christ" so it tells us that it came of flesh.