What is the problem with taking vengeance? (plz read below)?

Question

What is the problem with taking vengeance since vegeance is central in so many of the superhero stories. I'm asking this from a religious stand point.

Answer 1

"Vengence is mine," sayeth the Lord.

Answer 2

VEGEANCE IS MINE-SAYS THE LORD. WHAT WE WANT AND WHAT GOD WANTS ARE TWO DIFFERENT THINGS, PLUS THEN WE HAVE THE GUILT OF THE EYE FOR AN EYE THING GOING ON.

THERE WAS A MAN NAMED SUAL WHO WENT OUT TO STOP SOME RADICAL PEOPLE BY ARRESTING THEM AND HAVING THEM KILLED, BUT GOD DEALT WITH THIS MAN SAUL WHO BECAME PAUL A GREAT LEADER IN THE CHURCH THAT HE ONCE CONDEMNED.