|“||Skepticism has a long historical tradition dating back to ancient Greece when Socrates observed: “All I know is that I know nothing.” (...) Modern skepticism is embodied in the scientific method, that involves gathering data to formulate and test naturalistic explanations for natural phenomena. A claim becomes factual when it is confirmed to such an extent it would be reasonable to offer temporary agreement. But all facts in science are provisional and subject to challenge, and therefore skepticism is a method leading to provisional conclusions. Some claims, such as water dowsing, ESP, and creationism, have been tested (and failed the tests) often enough that we can provisionally conclude that they are false.||”|
Doubting and exercising Critical thinking is an important part of being rational. Doubt is totally opposed to unquestioning childlike faith that religious people value. Frankly religions including Christianity and Christian Fundamentalism are just so unreasonable in so many different respects. That's why once people stop being childlike and start using adult thinking skills faith too often evaporates.