It's universally recognized that Jesus' essential message was, the kingdom of God is at hand. And Mark tells us, in Mark 1:14 and 15, that Jesus came into Galilee, proclaiming the good news of the kingdom of God. And that word, "good news" or "gospel," comes right out of Isaiah. Isaiah predicted that one day there would be the announcement that God's salvation had arrived. So, it is, the good news, is ultimately related to the kingdom of God, and the kingdom of God is related to God's sovereign authority and rule and dominion. The kingdom of God has multiple meanings. It can mean God's overall sovereign rule over all of creation, or it can refer to his specific rule over the world when God reestablishes his reign, the consummation of his kingdom. Since human beings are in rebellion against God, have rejected God's authority, God promised in the Old Testament — we were just talking about Isaiah — in Isaiah's prophecies to one day reestablish his relationship with his people, to reconcile them to himself, to reestablish his authority and dominion and kingdom. And so, the promise of the kingdom is the promise that God is going reestablish his dominion and authority. The good news is the announcement that the time has arrived, that God's kingdom is at hand.