Christianity Today has an excellent article by Tim Keller which looks at the nature of the Gospel.
The gospel has been described as a pool in which a toddler can wade and yet an elephant can swim. It is both simple enough to tell to a child and profound enough for the greatest minds to explore. Indeed, even angels never tire of looking into it (1 Peter 1:12). Humans are by no means angels, however, so rather than contemplating it, we argue about it.
A generation ago evangelicals agreed on “the simple gospel”: (1) God made you and wants to have a relationship with you, (2) but your sin separates you from God. (3) Jesus took the punishment your sins deserved, (4) so if you repent from sins and trust in him for your salvation, you will be forgiven, justified, and accepted freely by grace, and indwelt with his Spirit until you die and go to heaven. Read More.
There are today at least two major criticisms of this simple formulation. Many say that it is too individualistic, that Christ’s salvation is not so much to bring individual happiness as to bring peace, justice, and a new creation. A second criticism is that there is no one “simple gospel” because “everything is contextual” and the Bible itself contains many gospel presentations that exist in tension with each other.
This excellent article demonstrates that while there are different Scriptural formulations and presentations of the Gospel, there is nevertheless an essential unity in the message. Tim goes on to suggest that the richness and variety of the Gospel message provides for different ways to present the good news which will allow people coming from different starting points to grow in their understanding of what God has done.