I am no longer a Christian due to some experiences in my life. I still feel the need for spiritual fulfillment but my logical side refuses to let me believe. If I went to church now I would betray myself.
I also have to express my displeasure over the lukewarm stances. If you are a believer, revel in it. Learn everything there is to know, grow and interpret. If you can't do that then you need to ask yourself the hard questions. Am I doing this because I am a coward? Do I need to believe in God simply because non-existance scares me? Am I just doing what is expected? I'll insert Revelation 3:15-16 here.
I'm getting married next year and my best man is a preacher's son. He is incredibly knowledgeable and intellectual. I pick his brain constantly and we always have philosophical discussions on the nature of faith and existence.
On the flip side another one of my groomsmen went to Florida Christian College and dropped out because he was unable to complete a research paper. Proving the Bible. He found that, for him, it wasn't possible and logic used in resources seemed flawed. He went to art school instead.
My wife to be is Pagan. A religion far older than Christianity, yet Christian practices stole greatly from and persecuted this religion. Why should I relate my self to that? She lived in Guam for several years and ,aside from the fact that almost the entire population is devout catholic and learns the will of god, children would spit on her, call her names, and even threw rocks at her simply because she had different skin.
Do I want to believe in god? sure. Will I believe in god? no. Will I go to church? no.
It would honestly take something irrefutable "a miracle" at this point in my life for me to return to Christianity.