Evelyn Underhill was one of the leaders of the movement rekindling interest in mysticism in the English-speaking world, and especially among Anglicans. Her 1911 book, Mysticism, is a spiritual classic. Much more than an academic study of the topic, it invites the reader into the experience of it.

Though mysticism be indeed the living heart of all religion, this does not mean tht religion does, or can, consist of nothing but heart. The Church is a Body with head, hands, feet, flesh, and hard bones: none of them any use, it is true, if the heart does not function, but all needed for the full expression of the Christian spiritual life. This acceptance of our whole life of thought, feeling, and action, as material to be transformed and used in our life towards God, is what Baron von Huegel meant by ‘inclusive mysticism.’ It alone is truly Christian; because its philosophic basis is the doctrine of the Incarnation, with its continuance in the Church and Sacraments. Its opposite, exclusive mysticism, the attempt to ascend to the vision of God by turning away from His creatures by an unmitigated other-worldliness, is not Christian at all. It ends, says that same great theologian, in something which cannot be distinguished from mere Pantheism: or, on more popular levels, in sloppy claims to be in tune with the infinite. —quoted in Love’s Redeeming Work: The Anglican Quest for Holiness, eds. Geoffrey Rowell, Kenneth Stevenson and Rowan Williams, p. 571