Rosenzweig holds Judaism unites man while Christianity splits him into two figures.

Evidence

In Jewish man, man was one, and a living one at that, for all his contradictions, for all the ineradicable conflicts between his love by God and his love for God, between his Judaism and his humanism, between patriarch and messiah. But in Christianity, this man separates into two figures, not necessarily two mutually exclusive and antagonistic figures, but two figures going their separate ways, separate even when they meet in a single person as is always possible. — Gil Anidjar, The Jew, the Arab, 498