Apologetics and Catholic Doctrine: Part II Catholic Doctrine, by Archbishop Michael Sheehan, is a classic textbook that systematically explains core Catholic beliefs (God, Trinity, Jesus, Holy Spirit, Church, Sacraments, Salvation) using clear, persuasive language for high school and college students, defending the Faith against objections, and providing a foundational understanding of what Catholics believe and why. It's known for making complex theology accessible, covering fundamental truths like the Eucharist and the role of tradition and scripture, making it a comprehensive guide to Catholic teaching.