Goodness leads to the truth in the final novel in the Scottish author's Wingfold Trilogy, following Thomas Wingfold Curate and Paul Faber Surgeon.   This final installment of the Thomas Wingfold trilogy from 1891 adds yet further dimensions to the personal search for faith and the nature of belief, exemplified in the characters of Barbara Wilder and Richard Tuke. Both Barbara and Richard must ask whether or not God's existence is true, what God's character is like, and what demands are placed upon them as a result. Wingfold's conversations with Barbara probe the foundations of belief with depth and profundity. Wingfold continually emphasizes the great truth: Everything depends on the kind of God one believes in.   All three of the Wingfold books address the logic and reasonableness of the Christian faith. MacDonald's characters must reason out belief. There will be no pat answers, no "humbug," as he called it. Christianity is reasonable, sensible, intellectually consistent. God's principles are true. This trueness pervades MacDonald's worldview as the foundation for Everyman's spiritual quest. As always, the stories upon which MacDonald weaves his spiritual themes are compelling in themselves. There and Back is no exception, with mysteries, romance, a disputed inheritance, again with an old castle and library, and a full range of fascinating characters spread along the spectrum of personal development.