"I use both a 'kingdom' and an 'eternal life' gospel. I find that many of my younger listeners are struggling to make choices in a world of endless consumer options and are confused about their own identities in a culture of self-creation and self-promotion. These are the people who are engaged well by the more individually-focused presentation of the gospel as free grace not works. This is a lot like the "eternal life gospel" of John. However, I have found many highly secular people over the age of 40 are not reached very well with any emphasis on personal problems. Many of them think they are doing very well, thank you. They are much more concerned about the problems of the world—war, racism, poverty, and injustice. And they respond well to a synoptic-like "kingdom gospel."
Instead of going into, say, one of the epistles and speaking of the gospel in terms of God, sin, Christ, and faith, I point out the story-arc of the Bible and speak of the gospel in terms of creation, fall, redemption, and restoration. We once had the world we all wanted—a world of peace and justice, without death, disease, or conflict. But by turning from God we lost that world. Our sin unleashed forces of evil and destruction so that now "things fall apart" and everything is characterized by physical, social, and personal disintegration. Jesus Christ, however, came into the world, died as a victim of injustice and as our substitute, bearing the penalty of our evil and sin on himself. This will enable him to some day judge the world and destroy all death and evil without destroying us."