I'm Christian, I think? I don't know. My church is named after the miracle at Lourdes, France.
- Do you believe that there is a single God (optionally having several aspects, but still ultimately being just one)?
- Do you believe the New Testament is, at the least, divinely inspired by said God?
- Do you believe that Jesus of Nazareth was not just your average Joe, or even your average prophet, but the honest-to-goodness "Son of God" (fairly broad interpretations of that phrase count)?
If yes to all the above, then you're probably Christian!
If not, but you still have a >50% confidence in the existence of a God, then between that and regularly attending a Christian church you probably still count as Christian.
Indeed, the only situation I can imagine where you'd be regularly attending a church and yet not count as a Christian would be if you were attending purely due to social factors, while belonging to another faith or being functionally agnostic or atheist. If you belonged to another faith you wouldn't be questioning whether you're a Christian, so perhaps you don't feel the evidence for the existence of any God is particularly strong? In which case you can still be culturally Christian without being a believer, but what terms you use to label yourself in that situation are pretty much up to you.
I for one am a filthy heathen, but I never pass up the opportunity to consume chocolate in quantities that are usually socially unacceptable.