Theory is defined in the scientific world as: A well-substantiated, comprehensive explanation of some aspect of the natural world, built from many hypotheses, laws, and repeated observations/experiments.
Science deals with the natural world, not the spiritual realm.
This is what science says about proof: Science deals with the real, physical universe through observation, experiment, and induction — not pure deduction from axioms. Because of this, science cannot deliver absolute, eternal proof.
While science theorizes that there is eternity, they cannot prove it.
Because God is both eternal and spirit, He will only prove Himself to those He chooses to reveal Himself.
We cannot choose to be chosen, that is in the natural world, not the spiritual realm.
Matthew 7:22-24 English Standard Version
22 On that day many will say to me, ‘Lord, Lord, did we not prophesy in your name, and cast out demons in your name, and do many mighty works in your name?’ 23 And then will I declare to them, ‘I never knew you; depart from me, you workers of lawlessness.’
24 “Everyone then who hears these words of mine and does them will be like a wise man who built his house on the rock.
In scientific terms this is a paradigm that is the shared framework that defines “normal science” for a scientific community at a given time. Those in verse 22 were scientific believers not spiritual believers, a paradigm.
This is why hearing Jesus is so important. He only talks to the chosen.