On the other hands, Christians can’t convince their own adherents to follow or protect the religion.
Judaism is united by one Torah. Religiosity is based on how much Law to accept and practice but all agree on the central tennent.
Islam is united (kind of) by the Koran though the different sects kill each other for fun.
Christianity is not united, too many derivations I think. At least they don't kill each other today as they did in the past, like Islam today.
The Church is a divided house.