Simplify the following text for a Grade 8 native English-speaking person.
Original: Martin Luther King , Sr. ( December 19 , 1899 - November 11 , 1984 ) was a Baptist Religious missionary , an advocate for equal justice , an early civil rights leader , and the father of Martin Luther King , Jr.
Simplified: The Reverend Martin Luther King , Sr. ( December 19 , 1899 â `` November 11 , 1984 ) was an African American civil rights activist and the father of Martin Luther King , Jr. . He was a Baptist minister .