When does a religious sect just become a whole other religion?

Question

For example, Jesus and his followers were considered Jews, but now they are call Christians. When did that change? I know there are other examples. Is there some sort of defining characteristic that makes a branch or sect a whole other religion.

Answer 1

When they get enough people. It's a numbers thing.

Answer 2

Jesus and his followers were under the Jewish law until He established his Church upon his death. At that point the Old (Testament) was done away with and Christianity was born.