A belief that a man the greeks called christ lived along time ago, was killed for his teachings and
a. rose from the dead
b. escaped to japan really wounded
c. didnt exist but is an pastiche of someone who represented the next phase im human development

His central message was
a. believe in me and you will go to heaven to sit beside me
b. sit beside me who is god and the holy spirit at the same time, Me myself I
c. be a good jew, not an observant one

Christian teachings are
a. whatever paul sez they are no matter what Jesus said
b. 10 commandments and flush the other 647 (see a) and proslytising the christian faith.
c. gentiles view of an older religion, judaism

Finally, what ever the other religion who is trying to kill you decides what christianity is.

regards,
daemon