Some of Jesus' statements in the NT seem to be targeted against or derivative from the beliefs and practices of the Essenes, an ascetic Jewish cult that left its literature in caves above Qumran. Vermes seems to provide the most authoritative translation into English. The Nag Hammadi Library in English , James M. Robinson, editor. Translations of early pre-Christian and Christian Gnostic writings. Had the Gnostics survived, Christianity would be a lot more like Zen Buddhism that it is now.
Christian prayer exercises in Eastern form.
Young Man Luther , Erik H. Erikson. A psychiatrist's insights into the personality of Martin Luther. One can gain an appreciation of how deeply Protestantism has been assimilated by its cultural milieu when one realizes that Martin Luther would never be accepted as a pastor in any contemporary Protestant church. Luther in Retrospect , Eric W. Gritsch. Valuable for its history of the encounter between Christianity and Science during the last 300 years or so, but not for its version of Process Theology.