Religion: One Flock, One Shepherd

Vouchsafe, oh Lord, our God, that . . . what Thou hast promised would one day occur, may come to pass in our time, namely, that there be but one flock and one shepherd.

This prayer for a united Christendom was repeated last week by Pope Pius XII. With the same prayer the Council of Trent in 1563 had closed its 18-year deliberations to combat the schism born of Martin Luther's theses nailed to the church door at Wittenberg. The Council failed to bring Protestant heretics back to the fold.

The ideal of "one flock and one shepherd" remained an ideal; the scandalous...