"The Church's spiritual motherhood is only achieved-the Church knows this too-through the pangs and "the labour" of childbirth (cf. Rev 12:2), that is to say, in constant tension with the forces of evil which still roam the world and affect human hearts, offering resistance to Christ: "In him was life, and the life was the light of men. The light shines in the darkness, and the darkness has not overcome it" (Jn 1:4-5)."