Today, I have with me for reading a some books on Esoteric Christianity.
The first is the classic Esoteric Christianity by Annie Besant, the Theosophist who helped found the Liberal Catholic Church. In her book, she explains the esoteric Christian tradition, covering inner meaning of Christian symbols, scriptures, liturgy and practice.
The second is Inner Christianity by Richard Smolley, who was an editor at the non-defunct Gnosis: A Journal of the Inner Western Traditions. What Annie Besant did in her day, Smolley does for our day, writing about the inner tradition of Christianity, and delineating it from the exoteric, outer or common understanding of Christian religion.
Also, as is my practice every day, the New Testament. I typically read the passages assigned in the 1928 Book of Common Prayer.
Finally, this little companion book, Metaphysical Meditations by Paramahansa Yogananda. I find some comfort in this little book. The meditations therein invite us to seek God's radiant presence within. Yogananda was a Hindu guru who believe in the essential harmony between Krishna and Christ, Yoga and Christianity. It was a major theme in his teaching.
If one wishes to approach God through Christ or Christianity, he or she must make a habit of reading the scriptures. If one wants to delve into the inner meaning of Christianity, that which leads us beyond dualism, these other books are a good place to start for the lay person.