Why did christianity grow in the roman empire?

Christianity grow by people going to church and saying amen

There are many reasons of why christianity grew in the Roman Empire. I'd go with these reasons:

1. Christianity were widely spread among poor people and slaves. Roman Empire was expanded and it was depended on slaves and poor.

2. Deceases spread all over the empire taking a lot of lifes, and people were inspired by the fact that there could be a life after death.