repent, and believe in the good news." Mark 1:15.
This is the essential message that Christ proclaimed at the beginning of his ministry, throughout his ministry, and it is the fundamental message sent to us now, today, these 2000 years later. There is a sense of profound urgency within the proclamation. The final coming of God's Kingdom may or may not be imminent, but that kingdom will come for each of us in our own time. We do not know if it will be soon or delayed. We can only know it will come inevitably and there is danger in denial and delay.
What is the Good News, a.k.a. the Gospel, that Jesus announces? It is that God loves us, and He wants us to live with him in happiness forever. What then is our response to this Good News? Repentance, i.e. a change of heart, a change in how we live and think, in what we do and in what we hold as important. St. Paul tells us that this world is passing away and so we need to change by not being so involved with the things that are already passing away. We need to even change ourselves emotionally.
1Cor. 7:30-31 Let "those who mourn [be] as though they were not mourning, and those who rejoice as though they were not rejoicing, and those who buy as though they had no possessions, and those who deal with the world as though they had no dealings with it. For the present form of this world is passing away." NRSV. (NAB)
Whatever is causing us sorrow should be seen in perspective. If you have lost money at business, why are you mourning over something that is already passing away? If you have made money at business, why are you rejoicing over something that really doesn't matter? You will loose it all eventually for you cannot take it with you into the kingdom and devoting to much love for it could deprive you of a place into the Kingdom. "You cannot serve God and wealth." Matt. 6:24 NRSV. (NAB)
The great danger to us is procrastination and denial. We don't want to believe that our time could be short. Almost anyone can argue to himself that he or she has years to go. Even a 70 year old, who does not have a terminal disease, can say that he may have 5 to 20 years left. The truth is that no one knows, and to fail to plan for the end is foolish, according to God himself. (See Luke 12:15-20.)