Letter to A Fallen-Away Catholic is an excellent defence of the Catholic Church.
It's a terrific response to 'Evangelicals', to every non-Catholic who claims to follow Christ, and especially to all of our relatives, friends and neighbours who have stopped practicing the Catholic Faith.
Letter to A Fallen-Away Catholic answers a myriad of questions regarding salvation and challenges the liberal hardly-Catholic education and training that moderns have received. It answers with a solid, charitable and easy-to-read logic that's mixed with clear, strong, irrefutable doses of Scriptural Truth and teachings from the popes, councils and saints. It's a powerful help in restoring unity in Christ and His Catholic Church and an useful resource for settling religious disputes and difficulties with those we care about.