What factors contributed the spread of christianity

Mostly conquest and colonization. Also trade. 

There are two major factors that, in my opinion, contributed to the spread of Christianity within the Roman Empire. The fact that the Roman Empire existed. Because the Roman Empire existed, it tied together people in many different areas 

the following best describes postwar era writers in their works:

progressive

many writers,authors,novelists,poets concentrated more on social art and social writing and stayed away from political writings.