Lutheranism is a movement within Christianity that began with the theological insights of Martin Luther in the 16th century. Luther's writings are credited with launching the broader Protestant Reformation. This attempt to reform the theology and practice of the catholic church led to the separation between a large number of Christians and the Roman Catholic tradition.[1] Today nearly seventy million Christians belong to Lutheran churches worldwide;[2] furthermore, many of the four hundred million Protestant Christians[3] can trace their tradition, at least in part, back to Luther's reforming work.