A painted portrait is rarely designed just to depict the sitter's "appearance." For one thing, the artist must catch in paint the sitter's "character." For another, the painting must be well suited to its intended setting and to the function it will serve there. The gospels, we might think, were intended simply to describe what actually happened. To do justice, however, to our four artists' skill, we must see how carefully each has caught the sitter's character; and how boldly he has explored the function that his portrait could fulfil.

There is a wonderful story to be heard in our gospels; and their setting offers a glimpse of some extraordinary moments in the history of the West: Rome in flames, mad Nero watching the blaze, Jerusalem destroyed, dire civil war ­- and amidst it all the gradual, inexorable spread of this new sect, the church. But there is more too: there is the role that our authors intended their stories to fulfil. "Description," we shall find, is not the half of it.

Who do you say I am? Each gospel offers its own answer and works with extraordinary skill to bring that same answer within its reader's grasp. Our own readers can watch those strategies at work and relish the care and courage with which they were pursued. And more: Some readers may find that our authors' strategies are still effective today; that we too can undergo the strange discovery into which the gospels invited their readers nearly 2000 years ago.

The gospels did not invite the reader to watch their evidence and assess it, but to be brought to a new understanding of its content: an understanding so alien to our ordinary ways of thinking and seeing that John could describe it only as "re-birth." The gospels have a crucial role; for this is a transformation, as our authors believe, to which no one would come unaided and on their own.

Our hunt, however, leads us to an unexpected insight. We were looking for four individuals; what we find are four traditions, ongoing communities within and for whose members, over decades and even generations, these texts were compiled, re-edited and brought to their final forms. To discover our witnesses is to discover the varied life of the church across half the Mediterranean and the most exciting, formative ­- and dangerous ­- decades of its early life.

Our detective work is taking a new direction. We can now search the gospels for the varied contexts in and for which these four "portraits" were painted. There is more to be discovered on this search than we could ever have expected to find. We hear for ourselves the hopes and fears of those early communities ­- small, beleaguered groups, but on fire with commitment to their new life.

Previous questions for author Robin Griffith-Jones

We frequently see movies and books that conflate Jesus' life into one story. What do we gain by seeing Jesus' life as four stories instead of one?

Read Robin Griffith-Jones' reply

What do you mean by your claim that the gospels are designed to effect a "revelation" in the reader?

Read Robin Griffith-Jones' reply