I recently went to a talk about rise of Christianity. The woman based a lot of her talk on Kautsky's The Foundations of Christianity*. She stated that originally, many Christians were urban poor, unemployed and so on, which is why many of the earlier gospels supported charity, helping the poor and so on. However, as Christianity spread among the rich, the later gospels reflected this change, which is why there are contradictions in the Bible, being written at different times and reflecting different values.
* I'm not sure if which her points were Kautsky's or her own (some she said were Kautsky's some she didn't specify).
