Warden didn't speak of "the theory" of evolution, but rather evolutionary theory and other formulations. Evolutionary theory is also not a belief with "believers".
Unlike some theories (like the General Theory of Relativity) there is not a simple set of equations that can be written down for evolution. The people who refer to evolution as "just a theory" aren't complaining about the lack of mathematical rigor.
Evolutionary theory is not any kind of belief or pure speculation. This is just false. (I suspect you are aware of this.)
Evolutionary theory doesn't have anything to do with any "atheist narratives".
Hans.
Backrgound
There are only two ways to view this. As a scientist or not. I prefer the former.
If you are in non scientist mode, theory , hypothesis proof can mean what you like.
Evolution can mean what you will.
If you are in scientist mode Theory. Hypothesis. Proof mean very specific things.
In non scientist mode, there is no "consensus" on what evolution means in colloquial usage except to say some vague assumption that it - the so far undefined "evolution" can somehow explain all or most of what happened certainly after the first cell.
But you and I in "work mode" as scientists cannot settle for other than definition rigor and you can only state what can be derived axiomatically and what are experimentally verified hypotheses can be promoted to theory. Whether they are mathematical or not.
So from the background let us deal with this case of woolly unscientific language by Warden..
Warden begged the question, when he questioned whether evolution was "just a theory" as if somehow deprecating a theory.
The question is whether there IS a "A theory of evolution" as validated by scientific means.
The answer is there is no single theory.
For example take the specuation that "all life" came from "evolution".
Quite apart from the fact nobody can decide when that started (some refer to chemical "evolution" before the first cell, who immediately run into problems as to whether chemicals are live!
Darwins so called theory was progressive small change is responsible for life (with or without survival of fittest)
It refers to no underlying process. Only an observation chain. So cannot be extrapolated beyond the observations so to make conclusions as regards all of life, he is just speculating...
And since in "life" terms he is referring only to observations of the last second of the last hour of life development, he cannot possibly demonstrate that hypothesis by experiment. So it is not a theory.
Let us be more specific and refer only to cellular development for which we at least have some molecular biological processes.
The simplest cell we know is Massively complex, more complex than any known chemical factories.
There is no conjectured pathway to those cells from simpler cells. The days of thinking that cells were just blobs of simple jelly as they did in darwins day is long gone. So there is no theory for evolution of cellular life that spans more than the last second of the last hour of cellular development.
Startting at the other end there is no hint of process to test to get to the first cell or from there to present cels so no hypotheis that encompasses most of life.. Nothing to test. No theory. Nothing EXCEPT speculation.
Clearly there are molecular genetic theories based on present life observation- starting with mendel and gene function - to the genome division and recombination that cover generational updates. Man as always used his observations well. Most of the life you see as plants and domesticated animals are the result of man using observations to adapt his envirionment.
But a myopic look at a few generations is certainly not what those who enter the "evolution" vs "creation" mean by evolution!
So those who think and claim that present science "explains" in any sense "life" using the word "theory of evolution" to do it clearly do not understand the words hypothesis, theory or scientific process.
When warden says "Just a theory" he should have said with scientific hat on "NOT EVEN a theory"
And if he ever comes up with his personal definition of this "theory of evolution" on which we must assume he based his remark, there is no doubt it either a/ it does not explain life in anything like entireity, or b/ he is speculating as darwin did. In neither case it is it a theory.
Alas in my field of science identifying what are assumptions repeated so often they became facts without proof, and distinguising them from fact, s is how many new discoveries are made/
In converse, Promoting the conclusion of evolution way beyond the evidence is a feature of atheists discussing origin of life.
I just tell it how it is. I am happy to separate what I "know" from science (with all the metaphysical limitations that has) with what I believe.
Most atheists cannot do that. Evolution explains life is the core belief of all atheists I ever met.! And those attacking creation are generally atheists on a forum like this. So that was fair comment too. It is not exclusive, some theists believe in evolution explained life from a created first cell. Others belief life appeared in late stage and developed from there. Either way they distinguish what they believe. Atheists can rarely separate what they believe from what they think (often wrongly) science can tell them.