So I recommend you watch the following and enjoy:
Atheism: Rationalism, Evidentialism, Verificationism
In summary, this video basically addresses the "Presuppositional Apologetics" which in essence claims something along the lines of "if everything you know to be true outside of your consciousness can be false, then how can you know anything?" (and then somehow magically claim that the Christian God in particular is the only way that you can make sense of the world, but we'll ignore that fallacy for now).
The Existential Crisis
Basically, it's true that outside my own consciousness, I can't really know for certain anything. The most basic assumption that I'm justified of making is "The fact that I'm contemplating my own existence - proves that I exist", or in Descartes's words: "I think, therefore I am".
That is the minimum that anyone can know for absolute certainty.
But if you stop there, then what's next? What's the point of living if all of this could be fake?
But even if this is some kind of a virtual simulation, it's an awfully convincing one. There's no way for you to actually verify whether this world is fake or not, other than, perhaps, dying. But then, what if you're wrong? What if when you die, that's it? Are you truly willing to take that chance?
The answer is simply: accept it. Make the most out of this "simulation".
The world has worked consistently so far, so make the best you can within its known boundaries.
Any "external knowledge" that you acquire, has a chance of being part of the fake simulation, but since you have no way of knowing that, just accept it.
Unlike in The Matrix movie, you are not offered a blue pill and a red pill. It's not that simple.
The blue pill is your (possibly simulated) life.
The red pill is death.
And furthermore, unlike in The Matrix, you never actually meet someone who you know took the red pill and came back to tell you about it (like Morpheus or Trinity). So there's absolutely no reliable point of reference for you to discern whether it's justified or not.
Not only that, but sooner or later, you're going to take the red pill whether you like it or not.
Everyone dies at some point, including yourself.
So why hasten this fate? Enjoy the blue pill while you can. Make the most of it.
This thought process is nothing new or extraordinary.
It's an experience which most people go through, and most of them accept their fate.
This is called "The Existential Crisis". If you also had it, don't worry. It's normal, and it's common.
My opinion? Is that this psychological phenomenon is simply a side effect of us being a sentient and self-aware species. In fact, this is the very definition of being "sentient" and "self-aware".
So if and when you have existential doubts, just remember that you're having these thoughts because you're sentient and self aware. In fact, you can feel empowered that you have these thoughts. Be grateful that you're not a bacteria or something, and carry on with your sentient life.
The Importance of Physical Experience
So now that we established that we have to at least consider this world as real, whether we like it or not, how do we proceed? Or, more accurately - how do we establish truth?
The answer is in the title - Physical Experience.
Our human bodies were granted with at least five physical senses: Sight, Smell, Touch, Taste and Hearing.
These are the senses which allow us to sense the world around us, and come to conclusions based on it.
This is how we gain experience. We hear things. We see things. We smell, touch and taste things. By "recording" these experiences in our memory, we construct our understanding of the world.
Experience as a whole, is the total memory of what these senses received as input during our entire lifetime.
Some would argue that "intuition" is somehow also contributing to our experience and understanding.
But do you think, for example, that 1+1=2 is intuitive? Do you think it's somehow "self-evident"?
It's not.
Math is an abstract representation of reality... of things we can see and touch using our body.
You know that 1+1=2 because if you take one apple and put it next to another apple, it can be represented as 2.
Separate the two apples and each one of them can be represented as 1.
Put them together again and you have 1+1, which is represented by 2.
In other words:
"2" is an abstract representation of 1+1.
"+" is an abstract representation of the action of putting together two sets of objects.
And "1" is an abstract representation of a single physical object (an apple, a chair, a table...).
So 1+1=2 is NOT intuitive. It's something that you learn from experience.
So you see, even the simplest things which you THINK are intuitive, are actually not. EVERYTHING you know for certain is based on experience. Experience which you gain using your 5 senses.
In conclusion, it's important to base your knowledge and understanding of the world on your physical experience. It's also important to accurately define your understanding.
For example, let's assume someone tells you that atheists eat babies.
Based on that, what kind of truth claim can you make?
Can you truthfully claim that atheists, in fact, eat babies?
No. You can't. You have not seen atheists eat babies. All that happened is that someone told you that atheists eat babies.
That's it. That's the only honest truth claim that you can make in this regard: Someone told you that atheists eat babies.
Does it infer that atheists actually eat babies? No. Does it infer that the person who told you this has actually seen an atheist eating a baby? No.
So, if you want to be honest, all you could claim in this scenario is that "someone told you that atheists eat babies", and that's it.
This is why it's more accurate (and honest) to say things like "I've heard that scientists discovered supporting evidence for evolution", and it's a lot more honest than saying "evolution is fact".
This is why it's also more accurate (and honest) to say things like "The bible claims that God has created the world", and it's a lot more honest than saying "God has created the world".
So inspect your own understanding of the world.
Be skeptical.
And if you want to be honest, don't rush into truth claims without physical experience.
