Where is the evidence for God? Where is the evidence for the truth of Islam?
There is evidence, lots of evidence. But what counts as evidence depends on a lot of factors. This is a basic truth about the way reason and rationality works and it is just as true about religious claims as it is about scientific (or mathematical) claims.
Imagine you are a scientist living in a world that is bitterly anti-science. The masses are taught from a very young age to distrust science, to look down on scientists, and to view science itself as charlatanism at best, a violent death cult at worst.
In this world, of course, there is no institutionalized science education. The vast majority of people have zero exposure to science in the classroom growing up. This results in a severe lack of scientific literacy in the general population. But the ignorance runs deeper than that because even universities are anti-science. The vast majority of university professors and cognoscenti worldwide view science with snarky contempt.
The only way to study science is in small, underfunded, understaffed independent schools scattered around the world. To study at those schools requires great personal and financial sacrifice on the part of students, which means that very few legitimate scientists are trained relative to the size of the population.
Now, for some reason in this world, the public believes that burning forests is great for the world’s climate.
As a scientist, you know better. You tell people that actually burning the world’s forests will cause an environmental disaster. Most people laugh at you and ignore everything you have to say given that you’re just a kooky scientist. Others are more respectful and tell you that you have the right to believe whatever you want as long as you don’t try to impose your beliefs on others by, for example, insisting that they’re true.
But there are some science skeptics who enjoy trolling scientists. So they start a dialogue with you. And they demand evidence. How do you know burning forests will lead to disaster? Where’s the evidence?
Now, you might be inclined to explain to them about greenhouse gases. But, of course, these people know absolutely nothing about chemistry or physics or biology. You could try to explain to them how CO2 traps heat, but they have no idea what chemical elements are, let alone CO2. You could tell them about how trees trap CO2 and give off oxygen and how living things like humans need oxygen, but then they would ask you for the evidence of all that. So you might try to explain some basic chemistry, but of course, that is not enough because ultimately chemistry as a body of empirical knowledge relies on molecular physics. So you’ll have to explain that and justify why that is epistemically reliable. And when it comes to understanding molecular physics, working knowledge of nuclear physics and even quantum mechanics is required, and on and on.
Obviously, these skeptics are going to understand very little of anything you might explain, let alone assume that what you’re saying is true. After all, these people had doubts about your initial claim as a scientist — there is nothing that would make them less doubtful about any of the other claims you would have to make about the supporting science that justifies that initial claim.
Now you might tell them: look, if you want to know with certainty how I know burning forests is a bad idea, you need to get a thorough science education and then do some basic experiments and then go onto advanced studies, etc., etc., and then you will have the evidence you need.
The lesson here is that what counts as evidence, i.e., compelling evidence that justifies belief requires a gigantic body of contextual knowledge. In discussions about science, that body of contextual knowledge is simply assumed on the basis of scientific authority. People trust scientists to know what they’re talking about, so they won’t press them too far to justify every single thing.
But when those same people talk about God, the skepticism is turned up to a whole different level, because religion has no intellectual or epistemic authority in the secular world we live in.
There is plenty of evidence for God, evidence far more compelling, consistent, and “objective” than anything in empirical science. But two things impede people from recognizing this.
First, contextual knowledge is not there. Islamic education is nonexistent for most of the world, including Muslims. Instead, Muslims worldwide are educated through secular models of learning. Obviously, that will impact Muslims’ ability to intellectually arrive at the conviction in the existence of Allah and the truth of Islam.
And if that weren’t bad enough, the second impeding factor is a very active anti-religion, the anti-Islamic current that permeates the culture, the media, the academy, etc., etc. The state of iman and conviction of Muslims around the world is severely impacted by these two factors.
The evidence for Allah and the truth of Islam comes from different sources that mutually reinforce each other. This is the way any body of knowledge works, including scientific knowledge, as the example above was meant to show. A skeptic can undermine any specific point of knowledge but they can do this in virtue of ignorance of the larger context or paradigm or episteme or plausibility structure or web of belief (or whatever other philosophical/sociological terms you want to use).