Conversing with theists is a bit like talking to a foreigner who has learnt English as a second language. Many of them have their own dictionary, their own meaning for some words that suits their religious agenda.
For example, let’s take the word ‘theory’. It has two meanings to scientists but only one meaning to theists. In everyday chat, we all use it as if it is synonymous with ‘guess’ and that is the only way that believers like to use it. Here is a general definition of theory: “an idea that is suggested or presented as possibly true but that is not known or proven to be true”. You can see why they like it – if that meaning is applied to scientific information, science can be construed to be as flakey as religious claims and, to many, science is the enemy of religion.
However, in science ‘Theory’ (I like to use a capital ‘T’ for this purpose) has another meaning, it’s “a comprehensive explanation of some aspect of nature that is supported by a vast body of evidence”. There is nothing stronger in science; a scientific ‘Law’ is not stronger, it’s just a Theory that can be expressed in the form of an equation.
Now, you need to know that, in nature, there is no such thing as ‘proof’: that’s why the definition refers to ‘evidence’ and, because there is no proof, nothing is absolutely certain, but to quote Wikipedia,
“Many scientific theories are so well established that no new evidence is likely to alter them substantially. For example, no new evidence will demonstrate that the Earth does not orbit around the sun (heliocentric theory), or that living things are not made of cells (cell theory), that matter is not composed of atoms, or that the surface of the Earth is not divided into solid plates that have moved over geological timescales (the theory of plate tectonics).”
That is an entirely different kettle of fish from ‘an idea that is not known or proven to be true’, which is the meaning given above for general usage.
Another important aspect of scientific Theories is that they must enable predictions that can be falsified. For example, the Theory of Evolution could be falsified by the discovery of, say, fossilised mammal bones in the Cretaceous era (it never has been).
So that distinguishes ‘guess’ from ‘Theory’ but it’s useful to know that scientists have a word for a halfway position. That word is ‘hypothesis’. A hypothesis is a proposal that is extrapolated from what is known but has no evidence for its specific proposition yet, also it must make predictions that can be investigated for evidence.
Whereas a Theory already has an archive of evidence, a hypothesis has nothing yet but might acquire some evidence in the future because it is possible to investigate it. It’s useful to think of a Theory as like a building with a foundation whereas a hypothesis is like an architect’s design for what might become a construction one day.
How might a hypothesis be converted into a Theory? By investigating one or more of its predictions to see which direction the observations support – confirming or denying… This requires repeatable observations and may need experiments – specially constructed investigations. Observations are the inspectors of ideas.
If a proposition cannot be investigated, it doesn’t qualify as a hypothesis, it is just a guess like, for example, “Thunder is caused by the god Thor doing some hammering in the sky…”