He is best known for his seven volume work Hablar con Dios (In Conversation with God), which has sold over two million copies in several languages, including Spanish, English, French, Italian, Portuguese, German, Dutch, Romanian, Slovakian and Polish. It consists of over 450 meditations, one or more for every day of the year, as well as three meditations for each Sunday, corresponding to the three-year cycle in the Catholic lectionary. An updated, four volume edition with over 550 meditations was completed in 2004.
He is a graduate in history from the University of Navarra, and holds a doctorate in Canon law from the Angelicum in Rome. He was ordained a priest in 1964, and has ministered especially to university students throughout his career. Carvajal was an editor of the magazine Revista Palabra for over 10 years, from the early 1980s to the mid-1990s.