1) You MUST include your citation (like a URL) to your source; and 2) ALSO a piece of DIRECT QUOTE to report research, with introductory/transitional phrasing in your own language. 
When you take even 3-4 words directly from a research source, you MUST place those between quotation marks.  For instance, you might write something like: According to History.com, Henry VIII’s first wife Catherine of Aragon was “demoted for bearing no son.”  Do you see how words you took directly from another source are placed within quotation marks?  You MUST to do this, or you risk a plagiarism charge.  Since you are being asked to conduct research, it’s perfectly fine that you are reading other sources, but you need to get in the habit of reporting and crediting your sources correctly.
Please note: Any time you use another source, you must use quotation marks around words taken from them and credit your source each and every time you use their ideas or words.  Do NOT borrow a large chunk from someone else and then just drop a citation at the end of your post.  That will not receive any credit.
1) Who is Martin Luther, and what did he do in 1517 that might shed interesting light on what’s going on with the debate about the power of traditional Roman Catholicism?