[source: Beyond Belief, p. 

DIDACHE IS ABOUT TEN YEARS EARLIER THAN GOSPELS OF MATTHEW AND LUKE
One of the earliest sources, for example, the Teaching of the Twelve Apostles to 
the Gentiles, shows that members of certain early groups of Jesus' followers did 
not think of themselves as Christians - as we think of Christians - as we think 
of Christians - as separate from Jews, but as God's people - by which some 
apparently meant Jews who revered Jesus as the great interpreter of God's law, 
the Torah. Written in Syria about ten years before the New Testament gospels of 
Matthew and Luke, this writing, known as the Didache (Greek for "teaching"), 
opens with a succinct summary of God's law...
[source: Beyond Belief, p. 15]