eschato-, eschat- (Greek: last, furthest, remotest, outermost).eschatologist: 
One who preaches about the last days; such as, death, resurrection, judgment, immortality, the end of the world, etc.
 
eschatology: 
1. A branch of theology that is concerned with the end of the world or of humankind.  
          2. A belief, or a doctrine, concerning ultimate or final things, such as death, the destiny of humanity, or the Final Judgment of God.  |