Now after John was arrested, Jesus came to Galilee, proclaiming the good news of God, and saying, "The time is fulfilled, and the kingdom of God has come near; repent, and believe in the good news."
There are various understandings of what the good news, or gospel, essentially is. This passage sums it up pretty well for me: the kingdom of God has come near; repent and believe. This kingdom is one over and against the powers and principalities of the age, one where God's love is the rule rather than who looks the best, does the best, earns the most money. This kingdom is one of both comfort and challenge, both hope and inspiration, both forgiveness and repentence, death of the old and instilling of the new. For me, this kingdom is personified in a man who lived with the lowly, believed God to his death, and through his resurrection is still present with us. Christ is risen because the kingdom is real. This is good news indeed.
Every time I drive a certain highway, I see a billboard with the following message on it:
Believe in Jesus
This is genuinely thought to be the good news for many Christians in the United States. The good news is that Christ died so you don't have to go to hell. Christ took on the weight of your sins so that God won't hate you any more. A good news that puts hell up front as a primary piece is a strange bit of good news. The first piece of this that makes no sense is the idea that simply by virtue of your changing your mind about a couple beliefs, you're on the road to heaven. 'Believe in Jesus.' I'll be fair and assume that 'believe in' is meant to take root a little deeper. However, that the sole aim of this belief is to avoid eternal torment is based on fear, not hope or faith or joy or even transformation based on inspiration. If I am inspired to repent, to change, by this 'gospel,' it is so God won't be so angry with me.
Meanwhile, what is revealed in a proclamation that the kingdom of God has come near is a proclamation that we are invited to this kingdom. There is cost, but there is also joy. It will change you and you will inspired to be changed...not to get on the 'nice' list, but to participate in what God is enacting.