Ok ok hear me out. I know everyone wants the two to switch places in season 3 and have Aziraphale saving Crowley and be an absolute badass but how about this.
He's in a situation where he has to choose to save the Earth, or... to save Crowley.
And he chooses Crowley.
Saving him is cool, but choosing him, as a contrast to him choosing to save the world and rejecting him in both s1 and s2, and now having him choose Crowley. And he does... He still saves the world. He saves his world.