Brother, to my humble opinion, doubt is the result of not pondering often. To take atheism as an example. In today's world, we are being bombarded by atheistic world view. Because people lack pondering, they directly believe what is being said. Believe me, i know this as being an ex-atheist myself. They tell you that there have been findings in country x and the bones that have been found are x amount of years old. However what you suddenly see in the article is NOT bones and some skull, you see a Neanderthaler from head to toe.
While logically speaking, how in the world have the based their finding of some ribbs and a skull in to a humanoid figure, with color eyes, skin color, clothes, amount of muscles..=_=!. 95% of it is based on lies. If one would ponder, you would indeed notice these small things. But if you would not ponder, you would doubt for example Islam instead. While based on logic, rationality and reason a Creator exists and doing exactly the same with using logic, rationality and reason, atheism is suddenly the most false believe there is. Mostly is based on assumptions and HOPES. There are facts and you base your believe on facts and there are believes and you base your believe on HOPES that it would become like that. This is the case with atheism, as they are desperately searching for this so called "missing link". When you have a trail of solid facts, the conclusion is based on those trail of solid facts. Atheism however is build mostly of a few facts (skull findings for example) and hopes (that humans somehow have a same ancestor as apes).
So my advice to you is, ponder often and in your heart make it..that you want to know..not that you are questioning something as false.
Maybe, even send your most critical question that you have via PM.