It makes no sense to do theological work in an ivory tower. The necessity of defining the concept "people of God" may be illustrated by at least four elements of present-day experience: the baffling fate and often shocking politics of the State of Israel since the six-day war in 1967; the anti-Jewish elements which still shame many books written for the church, and many Christian declarations about Israel; the stuttering progress in matters of Jewish-Christian unity; and, finally, the need for a united and unequivocal testimony to Jesus Christ who is a Jew and the Son of God, and as such the saviour of the world. Markus Barth combines Pauline exegesis, church history and dogmatics in this provocative contribution to an important contemporary debate.