If you want my personal definition of "Christian", it's this:
1. There is a god.
2. I'm not it, and neither are you.
3. Jesus is.
4. Therefore, Jesus is the boss.
After that, all the rest just sort of flows out of it. It is amazing how many doctrinal issues either instantly disappear or don't even matter anymore. You don't end up with all sorts or absurd "how many angels can fit on the head of a pin?" questions to argue about endlessly, with one camp saying 144,000 and another saying 144,000,000. Instead you get real questions, like "what does God want of me?"
It would be like having a major disagreement within a company over if the shoe size of the CEO is 12 or 13. The CEO doesn't care if you know his shoe size, he cares if you do your job or not.