How did christianity's ethical principles it spread?

Christianity's ethical principals promoted acceptance of god into ones heart to cleanse yourself of sin, and live an eternal life. For a variety of reasons the savior story format used in the bible indicates that people resonated with hope, forgiveness, kindness, and generosity. This could have been an internal response to the perhaps brutish world depicted, where forgiveness may have seemed somewhat out of reach. The theme of sacrifice is also proposed, which worked for the ruling class, who fancied themselves as superior, god-like, and the working class peasants, who probably needed to think they would die and do something better than farm potatoes.

Both stories have something in common