Schnackenburg follows the lead of the second century theologian Irenaeus of Lyon in speaking of one gospel in four forms. He describes a unity of faith underlying the diversity of the four biblical books designated as gospels, but he refuses to simply iron out differences in the interest of an historical whole. He sees the four gospels in historical sequence, with Mark originating the genre and providing a basis that is modified by Matthew, Luke, and John. All four gospels interpret the historical record with eyes of faith, but the movement from Mark to John is a movement toward greater "Christological profundity." For Schnackenburg, the four "forms" are best understood not as immovable pillars on which the good news is erected, but as streams that flow together to form a great river. Many readers will find that image appealing, and many will welcome Schnackenburg's lucid presentation of the often complicated relationship between faith and history. This is an excellent text to read alongside the large and growing body of historical Jesus research. Schnackenburg wrote it at least in part to hold the fragments generated by that research together, and it should serve a similar function for interested readers.