Just Be Changed!

In 'Mere Christianity', C.S. Lewis argues for the existence of God and defends Christian theology. The book is divided into four parts: the first argues for the existence of God based on the 'law of human nature'; the second defends Christian theology, including the 'Liar, lunatic, or Lord' trilemma regarding Jesus Christ; the third explores Christian ethics, including the cardinal and theological virtues; and the fourth discusses the Christian conception of God, particularly the Holy Trinity. Lewis also addresses topics such as free will, morality, sexual ethics, and the institution of marriage. The book is known for its clear and logical presentation of Christian apologetics and has been praised for its straightforward and humorous writing style.

The Summa Theologica is a comprehensive work divided into three parts. The first part deals with God, the creation of the world, angels, and the nature of man. The second part is subdivided into two sections: the first part of the second part discusses general principles of morality and law, while the second part of the second part addresses morality in particular, including individual virtues and vices. The third part, left unfinished by Aquinas, focuses on the person and work of Christ and the sacraments. The work also includes a posthumous supplement that concludes the third part and discusses Christian eschatology. Aquinas drew on Aristotelian and Augustinian influences and aimed to integrate faith and reason in his theological arguments.