The very concept of philosophical discussions raises philosophical questions about our ability to do so. Before we can even begin to seek or discuss truth, we must first assume that truth exists, and that we are capable of finding it. We can debate evidence, logic and doctrine all day, none of that matters if it doesn't exist, or if we're not capable of finding it.
In the world today, there are a number of religions claiming to be the truth. But each of them has a catastrophic failure when we get to this level of discussion. Only one faith in the entire world accounts for both the existence of truth and our ability to pursue it.
Let us start with the easy one: Agnosticism. Agnosticism is not a codified religion, but is rather a religious orientation. There are no scriptures that say "thou shalt not" or "thus saith the Lord". Agnostics are free to believe a diverse array of doctrines, because agnosticism has only one common element. That is, agnosticism is the literal denial of knowledge. Some agnostics don't take this too far. It's a simple "I'll believe what can be tested, but the supernatural cannot, therefore I'm staying out of it." In some ways, this is wise. Unfortunately, it's self refuting, because the very idea that one should test things before believing them cannot, itself, be tested.
Other agnostics take it to the extreme of "I know one thing; that I know nothing". This is an impossible way to live. Not only does it deny the very possibility of seeking truth, but taken to its logical extreme, an agnostic must surely know the basics? 1 + 1 = 2? The moon is made of rock, not cheese? Look before crossing the road, because a bus is a bus? Ultimately, you see that Agnosticism cannot stand against the argument from reason because it literally denies that truth can be sought.
Similar to agnosticism is atheism. Both deny God's place in philosophy, but atheism, rather than being "I don't know..." is more about "I do know that there is no God". This forces atheists to answer every question without God. Questions about morality. Questions about the future. Questions about the past. Just like agnosticism, atheism is also not a codified religion, and so no atheist is necessarily required to believe in Evolution. However, as Richard Dawkins put it, Evolution was designed in a vain attempt to make it "possible to be an intellectually fulfilled atheist". In other words, although atheists aren't required to believe in Evolution, they tend to do so.
But Evolution has its own catastrophic failure. If it happened, Evolution is not geared towards the pursuit of truth, but the success of reproduction, and even that being more of a passive result than an active goal. Darwin himself lamented "But then with me the horrid doubt always arises whether the convictions of man’s mind, which has been developed from the mind of the lower animals, are of any value or at all trustworthy. Would any one trust in the convictions of a monkey’s mind, if there are any convictions in such a mind?"
Who can blame him? If mankind is nothing but the next generation of randomly created life forms in 3 billion years, what is there to say we can trust our ability to pursue truth? We don't even have to compare ourselves to something as stupid as a monkey, we can look at other human beings. We're not all equally gifted in science, so who's to say any of us really are?
In fact, this is the very principle admitted in the Evolutionary explanation for the existence of religion. Supposedly, religion evolved because it provided our ancestors with a survival advantage. In other words, Evolution literally teaches that not only could humans evolve to believe lies if those lies are helpful to us, but that we actually did. And so how can you trust anything we believe? At the very best, we can assume we can know truth if that truth provides a reproductive advantage (which, it should be noted, belief in Evolution does not). Thus, Evolution cannot withstand the argument from reason because even if truth exists, we have no reason to assume we can know it. Most atheistic philosophies have the same pitfall. None of them can provide a foundation for the human pursuit of truth.
In the header image, I just lumped all polytheism together. I just needed to fill the 6th slot in the grid, and polytheism in general suffers from the same flaw. In Christianity, the Holy Trinity is one God. He's not three distinct gods, but three distinct personages within one God. But in polytheism, it is distinct gods. Distinct gods with their own desires, their own personalities, and their own grievances with one another. Who'd have thought mankind would invent gods that are identical to mankind?
In fact, that goes further than just their roles. Polytheistic gods may, themselves, even be just part of the creation. Some of them can even be killed, and a few have their own origins stories. This still leaves us with the unanswered question of what exactly is reality? Can we understand it or not? If different aspects of reality are controlled by different gods, it doesn't even make sense that truth exists, because it is dependent upon flimsy foundations. Thus, polytheistic religions cannot stand against the argument from reason.
Islam is even worse. Rather than several gods arguing amongst themselves, Allah is one god who is not even bound to himself. The Qur'an actually calls Allah the best of deceivers, and for good reason. Despite being the religion most hated in Islam, the Qur'an tells us that Christianity exists purely because of Allah.
How can this be? Well, according to Surah 4, Jesus was actually never crucified, but Allah made it look like He was by disguising someone else as Jesus. If a god is so deceptive that the religion he despises most was created because he felt like tricking us, what can we possibly trust? Maybe Islam is another trick Allah sent to man? What if Muhammad was actually just a frog that Allah made to look like a talking man? You see, then, that Islam cannot survive against the argument from reason because it does not describe a reasonable god.
I saved the "best" until last. Catholicism is perceived by the general public to be a legitimate branch of the Christian faith. And yet, based purely on its policy on dissent, we can see that even a corrupt form of Christianity destroys the idea that we can pursue truth.
An official Catholic dogma is that the bread and wine consumed during the Eucharist, upon being consecrated by a priest, becomes the literal flesh and blood of Jesus. The bread and wine are said to have two natures, the accident and the substance. The accident is how it appears. The bread and wine never actually change. A priest can bless it, chant over it, or wave a magic wand, the bread and wine never change. Yet the substance is what allegedly lies beneath the surface. It looks like bread and wine. It even tastes like bread and wine. All scientific experiments done on consecrated bread and wine will invariably reveal that it is bread and wine. And yet, we are told, it is the flesh and blood of Christ Himself.
And so, in the Catholic view, faith is not just the substance of things hoped for, the evidence of things not seen (Hebrews 11:1), but also the substance of things no sane person should ever want, and the evidence of the opposite of what we see. Who knows if other things have an accidental nature? Perhaps when God says He'll give His angels charge over us (Psalm 91:11), He's actually telling us that everything around us is an angel, maybe even disguised as the very chair upon which you sit?
The Catholic view goes even further, not only removing your ability to seek truth, but also to read the document given to you by the one who desires to give it to you. According to the Council of Trent, "no one, relying on his own skill, shall,--in matters of faith, and of morals pertaining to the edification of Christian doctrine,--wresting the sacred Scripture to his own senses, presume to interpret the said sacred Scripture contrary to that sense which holy mother Church,--whose it is to judge of the true sense and interpretation of the holy Scriptures,--hath held and doth hold," Translation? It doesn't matter what the scriptures say, God Himself is not as authoritative as we are. You can't pursue truth because if you try it without us, you're going to fail. And at that time, even risk capital punishment. Thus, not even Catholicism can withstand the argument from reason, because you can't even hear truth from God, if the Council of Trent has any validity to it.
But Christianity, in its purest form, lacks all of these problems. Truth exists, and God is it (John 14:6). God never changes (Malachi 3:6; Hebrews 13:8). God never lies (Titus 1:2). God is not divided (1 John 5:7). God created a very stable and predictable creation (Genesis 8:22; Psalm 104:5), which He commanded us to subdue (Genesis 1:28). We are commanded to test all things (Acts 17:11; 1 Thessalonians 5:21; 1 John 4:1). As Christians, we have the most solid worldview on the planet, because it is internally consistent, and it is the only one that allows us to understand that truth exists, and we are able to seek it. Whenever a human being discusses the concept of truth, they are unwittingly conceding the truth of Christianity.