Many scholars are now more convinced about the historical reliability of the Gospels than was the case a generation ago, writes Prof Paul Trebilco.
The Four Gospels - Matthew, Mark, Luke and John - are clearly very important for the Christian faith.
They are among our key sources of information about the life and teaching of Jesus and they also tell us what some of the earliest Christians believed about Jesus.
When we read a book, it helps to know what type of writing it is, since different forms of writing create different expectations in readers.
A novel is different from science fiction, which is different from a collection of poetry, and so on.
Most scholars now argue the Gospels should be understood as biographies.
Not the sort of biographies we would write today, but the sort of ''life'' that someone would write in the first century.
The Gospels show clear features of Graeco-Roman biographies, such as telling about the person through their words and actions, and a thematic rather than a strictly chronological approach to writing about a person's life.
There is also very little direct comment by the biographer about the person (relying instead on what the person actually did and said), very little about family background, and a significant focus on the person's death.
All these points are characteristics of first-century biographies, and also of the four Gospels.
A generation ago, scholars often argued the Gospel writers were not at all interested in giving ''the history of Jesus''.
It was thought they were only interested in writing about faith in him, and in giving early Christian preaching about him.
But clearly the Gospel writers were interested in what Jesus said and did.
They had strong historical intentions and went about writing biographies of Jesus, according to the practices of their day.
We are right then to look to the Gospels as sources of historical information about Jesus' words and deeds.
Biographers in the first-century would have looked for eyewitnesses of the events about which they wrote, and there are many indications the Gospel writers did this, too.
At the beginning of his Gospel, Luke tells us that what he writes has been handed on to him by eyewitnesses.
Another indication of eyewitness testimony is that a number of minor characters in the Gospels are named, people like Zacchaeus, Bartimaeus and Jairus.
They were probably eyewitnesses who first told their stories, which were then passed on as oral stories connected to their names.
Accordingly, many scholars are now more convinced about the historical reliability of the Gospels than was the case a generation ago.
But biographies in the first century were also written to commend a person as someone worthy of emulation, as someone who lived and died as a virtuous person, and so on.
This is exactly what the Gospel writers do - they show what they believe to be the importance of Jesus and they share their deep convictions that God was doing something radically new through Jesus' ministry.
They also want to show, for example, that Jesus' death is the key event in bringing God's forgiveness (in the case of Mark's Gospel) or that Jesus shows readers who God is (in the case of John's Gospel).
We might think the fact the Gospels were written from the position of faith, and from convictions about Jesus' significance, might take away from the value of the Gospels as sources for Jesus' life.
But in the first century, writers of biographies were all convinced of the significance of the person about whom they wrote.
The Gospel writers were no different. Historical value was not called into question by personal convictions.
That the Gospels were key literary productions of the earliest Christians shows they were totally captivated by the person of Jesus.
In fact, one unusual feature of the Gospels as biographies is that they were originally anonymous.
The titles of the Gospels (''the Gospel according to Matthew'' and so on) are slightly later and came to be used when the Gospels were collected together and so needed individual names.
They were originally anonymous because the authors thought their own names did not matter.
They were so focused on Jesus that they simply wanted to write about him.
Christian faith from the beginning has involved being captivated by Jesus.
• Paul Trebilco is professor of New Testament studies in the department of theology and religion at the University of Otago.