Funny Joke

So there was a plane and in that plane was 4 people a Pilot,Lawyer,Priest, and a kid. The plane is going down and fast but there was only 3 parachutes so the pilot says "I have a family and a daughter that is expecting" he grabs a parachute and jumps off the plane. The lawyer says "well I'm the smartest man on earth so I have to live" he grabs a parachute and jumps off. So now there is only 1 parachute left the Priest notices this and tells the kid " Son go ahead take the last one I have lived my life" The boy looks around the plane and says "wait we can both live" the priest says " well how can that be?", the boy says " because the smartest man in the world just jumped off with my backpack" ????