Having claimed, implausibly, that atheistic thinkers rely on some kind of narrow, self-serving conception of rationality, Uthman Badar illustrates what would be involved in his "broader" and true rationality by referring to the traditional arguments for the existence of God.
This is rather strange, since so much has been said by philosophical atheists about these arguments. They are, indeed, part of the religious heritage that merits rational critique. Accordingly, it's quite misguided to claim that neglect of these arguments is a weakness in contemporary atheism. If relatively little is said about them by some atheists who currently have a high profile, it's because they are so widely acknowleged, even by many (probably most) theistic philosophers, as being inconclusive. There are, of course exceptions - philosophers who think that one or more of these arguments is strong. But of course there are also plenty of atheists (as well as plenty of theists) who have produced searching criticism of each of them.
To his credit, Badar doesn't even say much to defend any of the traditional arguments and acknowledges that much has been said in response to them. His point seems to be that atheists are ignorant of the arguments or discount them from the start (because they fall outside of atheists' narrow, self-serving conception of reason). He almost seems to be saying that the existence of these arguments is news to people like me. But if that's what he thinks, it's obviously not the case.
In any event, Badar offers a version of the Kalam Cosmological argument as the strongest proof in his - or perhaps his organisation's - estimation. A problem here is that he does not set out the argument in a form that makes very clear what premises he relies on or how they are supposed to lead deductively to a conclusion. Usually this argument begins with a claim to the effect that anything that has a beginning, or that begins to exist, has a cause and that the universe itself is a thing that has a beginning (or, speaking tenselessly, begins to exist). The conclusion is thus that the universe itself has a cause. There then has to be some footwork to show that this can't go on forever and that there must be some kind of first or ultimate cause, which must be a thing that has no beginning, and must also be shown to have such attributes as personality and volition.
This all gets very murky very quickly. Do we really know that everything that has a beginning has a cause? If so, what is the meaning of the word "cause" here? It's not as if our notion of causation is entirely straightforward. If quantum events have "causes" in some sense, are the "causes" (perhaps statistical laws) necessarily the kinds of things that can be said to have beginnings and thus require causes of their own? If our notion of causation is such that quantum events don't have causes, doesn't this mean we should reject the major premise of the argument?
And why adopt it anyway? It looks like a contrived way of avoiding the more obvious, but disastrous, claim that everything has a cause - which very quickly provokes the question "What caused God?" There are questions as to whether the universe itself had a beginning in the same sense that objects and events within the universe do. That line of thought can quickly take us into conceptual issues about what it even means to say that something has a beginning, as well as to the latest cosmological theories and how well they line up with our concept (whatever it is) of something having a beginning.
There's then some footwork to try to show that the cause of the universe must be a personal agent rather than something impersonal, such as an unknown (to us) mindless mechanism that exists from eternity. Again, this footwork is typically very suspect, and I doubt that any assumptions supporting it have a rational basis.
Badar starts his version of the argument as follows: "the material world ... comprises of [sic] temporal phenomena that depend for their existence on other temporal phenomena and so forth. Such a series cannot continue to infinity, for if it did no one thing would satisfy its dependence and nothing would exist. The fact that things do exist necessarily implies a finite series and, in turn, the existence of a being who determined both the existence of this series and the specific attributes or properties that define it."
This is all very quick and confusing, but I suppose something like the standard version of the argument can be found here with some ingenuity. The idea seems to be that we can't have an infinite regress - an actual infinity - of caused things with beginnings in time. At some stage the regress must come to an end in something (Badar tendentiously calls it a "being") that was not caused and had no beginning. This is very dubious. He tries to give it some support - more rhetorical than anything else - later on in his article. But really, the most we can really say is that actual infinities are mind-boggling to beings like us. It's not at all clear that they are logically impossible (mathematicians seem to be able to work with them okay) or that they are any more mind-boggling than any of the alternatives once we start down this path of thought.
In any event, Badar tells us: "By rational extension, this being [sic] must be eternal and without beginning, otherwise it is temporal and forms part of the series. It must also be sentient for a timeless cause producing a temporal effect requires an independent will. Finally, effecting so grand a creation as the universe and all that it contains necessitates knowledge and power."
But none of this follows without a helluva lot more. E.g., where does Badar get the premise that "a timeless cause producing a temporal effect requires a rational will"? Perhaps he can support this somehow (some theistic philosophers have attempted to do so), but as it stands it is just a bald assertion with no particular evidence in its favour, and not even any particular intuitive appeal, at least to me.
And where does he get the premise that creating something as "grand" as the universe requires knowledge and power? I suppose that an intelligent being that consciously designed and created the universe would, indeed, have to be powerful and knowledgeable, so perhaps we should accept it if we get to the point of accepting the conclusion that an intelligent being consciously designed and created the universe. But we also know that highly complex outcomes can be produced over time through processes that don't possess power in anything like the sense that God is supposed to (though they must be "powerful" in the trivial sense that they can indeed produce such outcomes). Nor are such processes "knowledgeable" in any relevant, non-metaphorical sense.
I'm not going to claim that the Kalam cosmological argument is just hopeless. It can be refined in various ways to (purport to) give support to the various premises that it relies on in one place or another. However, even the best expositions of the argument end up being murky, puzzling, and inconclusive. I doubt that the version offered by Badar would convince anybody, relying as it does on assertions that simply do not appear at all self-evident.
Theists who believe that some kind of cosmological argument is adequate to prove the existence of something remotely recognisable as the Abrahamic God are welcome to keep trying. From historical experience so far, it seems like a futile effort, but no one can be certain of that in advance. Perhaps one day I'll encounter an argument that convinces me. I'm open to it. However, it will need to rely on premises that really are self-evidently true, or are supported by some kind of evidence sufficiently powerful to persuade an outsider to the belief system.
It hasn't happened, and I expect it ain't gonna happen ... but philosophical theists are always welcome to develop and refine their arguments.