Regarding Christianity....Is it possible to doubt an ideology you believe to be true?

Simply put, you are asking whether you can still be a Christian because you want to be a "good" person, but not have to believe in the fairy tales told in the best selling fictional story book of all time. My question to you is, why you feel that you need to believe in some super natural deity in order to be righteous and just. It sounds to me that you are on the journey to becoming an Atheist like myself and so many others, with the first stop being Agnostic. Once you start to doubt and ask more and more questions, you will find that religion offers very few answers.