The bloody crucifix cannot be made to fit a Cartesian mold. God, certainly, must not be allowed to interfere in the course of human events. [In The End of the Affair,] for Maurice (and Sarah, at first), the “sin” of God is not so much His existence, but His interference where He does not belong. Modernism can tolerate a vaporous divinity, or even a docile priesthood; it cannot abide, however, the taunting earthiness of faith.

For Greene, the sexual act represents an anti-type of Christian communion. In their adultery, Maurice and Sarah find what they believe is a fulfillment of real love. What, after all, could be more sensually intense and communal than sex? The vague eroticism which Maurice mistakes as love, Greene reveals to be a deformed type of true religious Love. The desperate orgasmic cry which Sarah lets loose during love-making is not erotically charged, but is rather a cry echoing from within her hollow soul. The sexuality which seems so carnal turns out to be distinctly less fleshy than the representation of the bloody crucifix. The modernist is not at all comfortable with flesh—not in its truest definition. Greene must be read in this way. Sex as a sensual pleasure provides an image in negative of true Communion. When Maurice finally begins to realize that the “man” whom Sarah had left him for was God Himself, Maurice treats God like a sexual interloper. God has stolen Sarah’s affection, even her physical presence from him. God has wooed her like any lothario, and ravished her.

This is what makes the miracles in the last few chapters of the novel so important. Sarah’s body, which was once misused for banal sex, is transformed into a conduit of grace (in a very Catholic manner).