and think what is good for you.
A big example is the egyptian scientist who was a muslim believer then changed because he had doubt and finally became a stronger Mulim believer.
Here is some information on him which I found on wekipedia.com
Mustafa Mahmud says that it was not due to denial or obstinacy or disbelief. It was only reexamining a methodology, of which he started without long-established maxims. Along that journey, he was ever close to Allah. Nevertheless, he started thinking of religion from the very beginning… from the beginning of the innate-nature, and what it acknowledges without inherited values. He finished his journey stronger in faith, firmly-established in his belief. The journey had a great influence on all his eighty-nine books he has written.
Those Muslim who fight each other do not understand the core of Islam and they think that islam is only having to do with bear or mostach.