If the wandering jewish rabbi called Jesus wouldn't have been crucified by the Romans, there would exactly zero Christians today. This execution became one of the core elements of later Christian ideology and identity. The necessity of assessing a Christian contingent results of this historic misjudgement of some Roman top officer.
Jerusalem suburb of Even Sapir evacuated as wildfire spreads (Haaretz)
from the article: Central Bureau of Statistics: 2.1% of state's population is Christian