How did Christianity take over the Roman World?

Christianity started out with a handful of followers in 30 CE - Jesus' remaining disciples and a few female supporters. But within 300 years there were some 2-3 million Christians in the world, including the emperor of Rome. How did *that* happen? How did an offshoot of Judaism come to take over the world, to the extent that it eventually became the religion of the West for centuries, down to the modern age? The answers are not actually what most people would suspect, and in this episode we lay them out.