Certainly the followers of Ritschl who will acknowledge no
traits of the gospel save those of which they find direct witness in the
Gospels, thus ignore that the Gospels are themselves interpretations.
This undue stress upon the documents which we are fortunate enough to
possess, makes us forget the limitations of these documents. We tend
thus to exaggerate that which must be only incidental, as, for example,
the Jewish element, in the teaching of Jesus. We thus underrate phases
of Jesus' teaching which, no doubt, a man like Paul would have
apprehended better than did the evangelists themselves. In truth, in
Harnack's own delineation of the teaching of Jesus, those elements of it
which found their way to expression in Paul, or again in the fourth
Gospel, are rather underrated than overstated, in the author's anxiety
to exclude elements which are acknowledged to be interpretative in their
nature. We are driven, in some measure, to seek to find out what the
gospel was from the way in which the earliest Christians took it up. We
return ever afresh to questions nearly unanswerable from the materials
at hand. What was the central principle in the shaping of the earliest
stages of the new community, both as to its thought and life? Was it the
longing for the coming of the Kingdom of God, the striving after the
righteousness of the Sermon on the Mount? Or was it the faith of the
Messiah, the reverence for the Messiah, directed to the person of Jesus?
What word dominated the preaching? Was it that the Kingdom of God was
near, that the Son of Man would come? Or was it that in Jesus Messiah
has come? What was the demand upon the hearer? Was it, Repent, or was
it, Believe on the Lord Jesus, or was it both, and which had the greater
emphasis? Was the name of Jesus used in the formulas of worship before
the time of Paul? What do we know about prayer in the name of Jesus, or
baptism in that name, or miracles in the name of Jesus, or of the Lord's
Supper and the conception of the Lord as present with his disciples in
the rite? Was this revering of Jesus, which was fast moving toward a
worship of him, the inner motive force of the whole construction of the
dogma of his person and of the trinity?

In the second volume Harnack treats of the development primarily of the
Christological and trinitarian dogma, from the fourth to the seventh
centuries. The dramatic interest of the narrative exceeds anything which
has been written on this theme