Can one mythical creation forgive another mythical creation? Sure, why not. It might make an interesting allegory. A divine comedy even. Jesus is pretty cool and Satan sounds like he'd be up for it but I don't know if Jesus dad would let him out to play. After all in 1914 Satan waged a war in heaven and his rebel army attracted the support a third of old Jehovah's angels..
Satan: Please forgive me Lord, for pretending to be a talking snake in Eden. I didn't know your dad was so sensitive about his fruit.
Jesus: OK it is forgiven, sin no more.
Satan: And forgive me Lord, It was a quiet day in heaven and Job seemed like a sure bet.
Jesus: OK it is forgiven, sin no more.
Satan: And forgive me Lord, you looked knackered when I offered you bread.
Jesus: OK it is forgiven, sin no more.
Satan: And forgive me lord for offering you the Roman, Chinese and Aztec empires.
Jesus: OK it is forgiven, sin no more. Shit here comes Jehovah..Quick get behind me!
Satan: ..like the time I entered Judas?