Donne wasn't afraid to use sexual themes, language, and imagery to make a spiritual point...or vice-versa. He seemed to think that the erotic life had an almost mystical power to unite people, or to unite people with God. In some of Donne's most famous religious poems, like the "Holy Sonnets," he asks God to treat him like a lover and even to "ravish," or rape, him. "The Flea," on the other hand, is more of a love poem, but the speaker nonetheless treats sex as if it fulfilled a religious purpose within the sacrament of marriage. Whereas in the modern age sex and religion have often seemed opposed, in Donne's poetry they have a natural and familiar relation with each other.