Religious Expansion
The graphic below shows the founding and expansion of most of the major religions of the world as a function of time.
I write this to show that while some may argue that Islam is a violent religion who's goal is to take over the world... I would like to point out that Christianity has actually been the most successful at spreading it's religion, at least in terms of area.
I think we can include the more recent times in this argument. I'm speaking of the Spanish, French, and British Imperial expansions starting in the 1600-1700 and continuing with Unites States Imperialism today. In the case of England, France, and Spain, they are and have been Christian nations, in the case of the United States, although secular in its foundation, is predominantly Christian. I also must point out that most of this expansion of Christianity has been and continues to be as bloody as any Muslim expansion/conquest. For example, the Spanish inquisition, the Spanish missions in the Americas, the British rule of India, the expansion of the United States across the North American Continent, etc, etc, etc.