Despite the constant conflict between Christianity and Islam throughout history

Despite the constant conflict between Christianity and Islam throughout history we have seen that there are some great similarities in them. What similar paths did these religions take as they spread from small groups to millions of believers across whole continents? How did they spread from small groups to large swaths of believers?There are many answers to this question but the best contributions with be specific about the parallels in thehistoryof these two religions rather than their specific beliefs. Then please respond to at least two students with substantive thoughtful reactions to their ideas.