The good news of the kingdom can only be received through repentance and belief. The gospel is the good news, the truth. If we see it and accept it as our reality - instead of just good advice - it should cause us to recognize our need for it and come into repentance as we evaluate our lives against it. Repent is the most gracious word in the English language. It’s simply the opportunity to change your mind (repent), and act accordingly (believe).
The beginning of the good news about Jesus the Messiah, the Son of God, as it is written in Isaiah the prophet: “I will send my messenger ahead of you, who will prepare your way, a voice of one calling in the wilderness, ‘Prepare the way for the Lord, make straight paths for him.’”
Mark 1:1-3 (NIV)
“The essence of other religions is advice; Christianity is essentially news. Other religions say, ‘This is what you have to do in order to connect to God forever; this is how you have to live in order to earn your way to God.’ But the gospel says, ‘This is what has been done in history. This is how Jesus lived and died to earn the way to God for you.’ Christianity is completely different. It’s joyful news.”
Timothy Keller - Jesus the King