Last week the local public library had a book sale of old library books and donated books that were either removed from the shelves, or never made it there in the first place. I didn't know about the book sale until it was almost over, but there were many books of all sorts to be had. The stock was fairly picked over, but I think I managed to find a couple of gems, "Early Christian Doctrines", by J. N. D. Kelly (this edition published in 1978), and "Man and God: Passages chosen and arranged to express a mood about the human and divine", by Victor Gollancz (published in 1951).
Both books are exactly what they claim to be. The Kelly work is, as far as I can tell so far, a comprehensive summary of doctrines, beliefs, and ideas that were formed during the early centuries of Christianity. It is a bit dated, obviously, but I think I'll find it very informative.
The other, "Man and God" by Victor Gollancz, also seems very intriguing at first glance. There are quotes and passages assembled from both the Old and New Testaments, noted Rabbis, the Zohar, Soloviev, Saints of both the Eastern and Western Christian churches including Julian of Norwich and John Chrysostom, Beethoven, Chuang Tzu, Goethe, the Bhagavad Gita, C. G. Jung, John Macmurray, Dostoevsky, William Blake and many others. I think it's remarkable, but I haven't had much of a chance to really get into it yet. If I enjoy it as much as I am anticipating, it should be well worth the pennies I spent on it.