There are only a few books I turn to again and again: when I have questions, doubts, or just a need for inspiration.
One of them is Bishop Kallistos Ware's
"The Orthodox Way." It is lucid in discussing the basics of Orthodox faith and theosis. Topics include the Trinity (in Father, Son and Holy Spirit and as One), holiness, and the ultimate destination of our souls.
The writing style is noteworthy. What Vladimir Lossky did in exquisite detail (in his "Mystical Theology of the Eastern Church"), Bishop Ware did concisely. It is written with the brevity of a sage who speaks with the essential concision of the Spirit. In other words, instead of long, detailed, tightly reasoned paragraphs, Bishop Ware wrote in a style that most people --intellectuals and non-intellectuals-- can understand and profit by. This isn't dumbed-down Orthodoxy; this is Orthodoxy explained simply: with the holy simplicity of someone whose words speak volumes, intellectually and spiritually.
It is also well-geared to people (like myself) who spent years searching for their way to God and who want something deeper than an overview of the basics. He does so, precisely, by delving *deeply* into the "basics" --God, the Trinity, and how to live in ever-deepening union with Him.
I highly recommend "The Orthodox Way" to all.
-- John