John 19:28
“After this, Jesus knowing that all things were now accomplished, that the scripture might be fulfilled, saith, I thirst.”
Why is it that I can’t generate my own air, water, or food?
It is because Jehovah God wants to remind you, on a moment by moment, hour by hour, day by day basis, that you, as a human being; cannot exist on your own.
He wants you to recognise that, with every breath you take, every drink you drink, every food you eat, that YHWH, Jehovah God, is the One who sustains you.
(For He is the One who supplies all our needs from His riches)