The dangers is that every religion, including the Catholic one, says "I have the ultimate truth." Then you start to rely on the priest, the mullah, the rabbi, or whoever, to be responsible for your acts. In fact, you are the only one who is responsible.
For the great majority of mankind are satisfied with appearances, as though they were realities, and are often more influenced by the things that seem than by those that are.
An ingenious compound of desirability and appearance. Discovery of truth is the sole purpose of philosophy, which is the most ancient occupation of the human mind and has a fair prospect of existing with increasing activity to the end of time.
But speak the truth, and all nature and all spirits help you with unexpected furtherance. Speak the truth, and all things alive orbrute are vouchers, and the very roots of the grass underground there do seem to stir and move to bear you witness.
The life of a thinking man will probably be divided into two parts -- the first in which he desires to exterminate modern thinkers, and the second in which he desires to watch them exterminating each other. ... Suppose, for instance, there is an old story and a new skeptic who is skeptical of the story. We have only to wait a little while for a yet newer skeptic who is skeptical of the skeptic. He will probably find the old notion actually a help in his new notion. This process is an abstract truth applying to anything, apart from agreement or disagreement.
The reason why any one refuses his assent to your opinion, or his aid to your benevolent design, is in you: he refuses to accept you as a bringer of truth, because, though you think you have it, he feels that you have it not. You have not given him the authentic sign.