The Protestants made the most radical break. Two of the principal issues raised by Protestants were
''[[sola scriptura]],'' the doctrine that the Bible alone is the final authority for Christians (which is also a denial of the infallibility of [[Sacred Tradition]], the Pope, and the infallibility of ecumenical Church councils) and ''sola fide,'' the doctrine popularized by [[Martin Luther]] that faith alone, as opposed to faith and good works both, is sufficient for salvation.
[[Image:Cathpop.jpg|right|thumb|350px|Catholics in the world.]]
==Organization==
The Pope and the the international leadership of the Church are based in [[Vatican City]], a sovereign elective monarchy and an enclave of [[Rome]] established by the 1929 [[Lateran Treaty]].
The Catholic Church has a complex hierarchy of clergy, including (in descending order of rank):
*[[Bishop]]s
*[[Abbot]]s
*[[Monsignor|Monsignori]]*[[Archpriest]]sArchpriests
*[[Priest]]s
*[[Deacon]]s