Busiek is known for his titles Astro City, Avengers, Shockrockets and Superstar. He said the following on an Astro City mailing list when asked about his religious beliefs:
"I'm an agnostic, to the extent that I think about it at all. I consider religions interesting, and the idea of a higher being or beings within the realm of possibility, but I haven't heard or seen anything yet that would make me a believer.
"However, I don't require my characters to share my approach to these things -- as is doubtless pretty obvious..."