In my opinion there is two ways to look at every scenario, the first being what you believe, the second being what you feel. For revenge my beliefs are to turn the cheek and accept what has been done, but as anyone who knows me knows my feelings are about as polar opposite of that as possible. Personally I could see myself depending on the scenario lean either way. For example lets say I told my best friend that I liked this really cute girl and then told him NOT to tell anyone else and rather then listen to me he goes and tells the entire school. In that situation I would turn my cheek, but remember that next time. On the other hand in an example where lets say I am a boss and have to fire someone from my company and they come and hurt my family or someone/thing to get back at me. Most likely I would react with revenge and probably anger. I think the biggest part of whether I turn my cheek or not is if someone gets hurt or if I am put into a life altering position. A great personal example of this is with my soccer team. I was playing goalie and was doing what I was suppose to be doing. Sadly I got scored on because a defender made a mistake. The defender, trying to escape the blame blamed me for his mistake. Instead of taking revenge and yelling and accusing him of making the mistake I just turned my cheek and continued to play. He later came and apologized to me. Now for the example of Medea I believe that she is justified in revenge, but should take the moral high road. The main reasons why I believe she is justified is because of Jason she is cursed by Aphrodite which makes her turn on her own family and country(not her fault). After killing her own family to allow Jason to escape and get the golden fleece, she then produces children. In those times and today's she has gone over what anyone could expect. In addition to that marriage to me is a  inseparable bond, which makes me take Medea's side rather then Jason's. To conclude, it depends on the situation whether I believe in revenge or not, and in the case of Medea I believe she has the right, but should take the moral high ground instead.