I'm a Philosopher. I believe our main faculty is reason and through reason and only reason can we acquire Truth. Truth separates belief and opinion from "reality" (truth).
One argument i encourage anyone to read would be the Kalam Cosmological Argument. I think it's simple yet amazing and is irrefutable in my opinion.
According to quantum mechanics, nothing is real until observed (e.g. light is a particle or a wave depending on the way you observe it). Quantum mechanics has been scientifically proven to be true. Thus, objective truth does not exist; the only things that exist are our subjective perceptions.
On Kongregate I once tried to convince a guy that you can't prove clouds exist objectively. We know clouds exist because we've seen them every day of our lives. However, in the perspective of a rat that had lived its entire life in the sewers, it had never seen clouds. Thus, to the rat, clouds do not exist.
Of course, if this is true, then nothing is real. Everything we've known, learned, and discovered could all be a lie. Which is part of the reason why I don't think existence has a meaning or purpose.