Bob therapizing God and the Devil when the former forgets the latter's birthday and then browbeating them into raking his lawn (after they trashed it playing croquet).
Bob getting the Devil out of his house by singing Tony Orlando songs. It wasn't as complicated as it sounds.
Smeck standing up to Satan and chewing him out.
What're God's final words to Satan in the first episode? "Go to hell."
A meta example for the creators who decided to take the high road and make God a likable, if flawed, character while also making playful (not malicious) jabs at Christianity when they could've easily just gone the other route like many other shows. Sadly, people didn't see this and saw the show as offensive to Christianity, which is why the show didn't last.
How God convinces Bo that he's the real deal after his simple magic tricks don't cut it: he turns huge, makes the bar's walls fall to reveal a cloudy heaven and makes a bear on a bicycle fly by with a banner reading "It's Him!"
A minor example doubling as a Funny moment, but near the end of There's Too Much Sex on TV as a sick Donna is dropping off Megan and her friends off at the concert, Andy hugs his sister and says have a great time... and puts a sign on her back saying First Concert which will most likely cause her embarrassment. Considering how much of a Bratty Teenage Daughter Megan is (Heck she even made her mother take her and her friends despite obviously being severely ill), this is a somewhat satisfying comeuppance for her.
At the end of "Andy Runs Away" Andy, with God's assistance, kicks a soccer ball into outer space.