Nothing to do with Tom Hanks here... although I would say that some spoilers are to be included, so for those not up with the latest episodes, be weary.
Angels are creatures of God, having been created by him for some reason unbeknown to us. Then you've got the Archangels, another batch of superior Angels, that by all definition, are far more powerful than anything on Earth, or so it seems.
Then you've got Demons, by all definition, a creation of Lucifer. That being, Lucifer actually created the first Demons himself. Yet, when evil people die, they go to Hell and become Demons, when good people die, they don't go to Heaven and become Angels, they just die.
My only way of looking at this (from a logical stance) is that both good and evil people die, and pass on to whatever awaits from death. The only people to actually go to hell, are those that either have some deal with a Demon (crossroads), or have been led there by a different path. It seems to be the only scenario which makes sense, else Hell would be full up, and would surely outnumber the Angels thousands (if not more) to one.
In addition, if Lucifer created an entire species for himself, what is to stop Gabriel, Michael and Raphael doing the same? Couldn't each Archangel essentially have their own army, in the case of Michael and Raphael, to fight Lucifer?