Praying respawns you away from the action where you died. If another player is around or you see someone die this is how you revive them on the spot.
1: Have the dead player move a few feet from their point of death
2: The living player locates the ghostly connection from the dead player to the point of death
3: The living player places empty hands on the connection (no weapons out) and it will begin to glow blue
4: when the ghostly connection is completely blue the player will be revived