Tyler Cowen calls this piece, on Rawls' relationship to Christianity, "one of the best mid-length essays I've read in some time." I concur. Here's a passage from Rawls' senior thesis, entitled " A Brief Inquiry into the Meaning of Sin and Faith" (and written, as the title suggests, when he was still a believer), that gives you a taste of the Christian thinker he might have been:
We reject mysticism because it seeks a union which excludes all particularity, and wants to overcome all distinctions. Since the universe is in its essence communal and personal, mysticism cannot be accepted. The Christian dogma of the resurrection of the body shows considerable profundity on this point. The doctrine means that we shall be resurrected in our full personality and particularity, and that salvation is the full restoration of the whole person, not the wiping away of particularity. Salvation integrates personality into community, it does not destroy personality to dissolve it into some mysterious and meaningless "One."
I wonder whether the young Rawls qualified his use of the term "mysticism" elsewhere in the essay, since what he's critiquing here strikes me as a particular form of mystical pursuit - the kind that we associated with pantheism in general, and Eastern religion in particular. The mysticism that's specific to Christianity - from John on Patmos to Saint John of the Cross; from Teresa of Avila to Teresa of Calcutta - has always sought a union with God that specifically doesn't exclude particularity and distinction, or seek the dissolution of individuality in the warm bath of divine love. This is why the image of romantic love (brides and bridegrooms, a lover seeking his beloved, etc.) has long been a dominant metaphor in Christian mystical writing: It evokes a union that achieves intimacy and ecstasy without sacrificing personality or bodily integrity - an encounter that brings us face to face with God, but doesn't require our being subsumed into Him.
But I suppose I don't have to wonder exactly what Rawls meant: I can go buy the book.