Simplify the following text for a Grade 11 native English-speaking person.
Original: Following Muhammad 's death in 632 , the early leaders of the Muslim nation were called `` Khalifat Rasul Allah '' , the political successors to the messenger of God ( referring to Muhammad ) .
Simplified: Some of the early leaders of the Muslim community following Muhammad 's ( 570 â `` 632 ) death called themselves `` Khalifat Allah '' , meaning representative of God . But the other title of `` Khalifat rasul Allah '' , meaning the successor to the prophet of God , became the common title .