Kingdom of God and Repentance?

I am working on a new lecture on Mark for my intro to Scripture class and I wanted to talk about what Jesus means when he says the Kingdom of God is near. If you notice (1:14), he also tells his hearers to repent. How could this be good news? Why does Jesus announce the Kingdom and call for repentance? I appreciated Morna Hooker’s thoughts

“God’s Kingdom means ‘territory under the rule of a king’. In this case, of course, the ‘territory’ is the world, which has fallen into enemy hands; men and demonic powers have usurped the throne. But now the time is at hand when God is going to restore his rule, and that means the punishment of the wicked, as well as salvation for those who have been faithful to him. It is a time of judgment—which means that there is need to repent, even though Jesus’ message is ‘good news’” (Studying the NT, 24, Hooker)