A concise, practical primer presenting the essentials of Eastern Orthodox belief and daily spiritual practice for those approaching or living within the Church; it explains core doctrines, the liturgical cycle, sacraments and the role of icons and saints, and gives straightforward guidance on prayer, fasting, confession, repentance and ascetic struggle. Woven through are warnings about modern Western influences and encouragement to pursue the interior life and transformation (theosis) through obedience, humility and participation in the sacramental life.