He stands between them and the gates of heaven above, symbolizing his role as the guide to a new eternal life.
The best example comes from the Bible's Book of Revelation.
Meanwhile, Rachel's boyfriend and student of medicine Liam seeks her nearby the night-club.
They symbolize how it is impossible to escape the bounds of death; impossible to ever break free of the ultimate truth: That one day, death will come and take us with him.
The Grim Reaper was seen as a collector of souls, the messenger of the dead and most important of every guide that came to all mortals.
These are some personifications of death that appeared around the same time or after the appearance of the Grim Reaper.