Deena,
The books Peril and Peace, Monks and Mystics, A Story of the Middle Ages, and Mystery of History III are all very strong in Christian/Biblical content and tone, making the daily stories a blessing to read. Diana Waring's What in the World is a terrific Biblical overview of the time period and God's plan for mankind, bringing the pieces of the puzzle together in a Christ-centered way. In addition to those resources, Hidden Treasures in Philippians will look at other portions of Scripture beyond the book of Philippians as kiddos will be asked daily to study God's word. The kiddos will also memorize daily from Philippians 1 and sing it.
Looking up and copying portions of Scripture for history and for science is also a part of the plans each week, along with very God-honoring books for science within every science book choice for RTR. Exploring Creation with Astronomy, A Child's Geography, Exploring Planet Earth, Along Came Galileo, and the Sower book on Newton are written from a Christian perspective and are full of references to God and His word. Kiddos will also be reading and applying passages from the Bible in conjunction with the Purity study each week for Beautiful Girlhood and Boyhood and Beyond as they learn how God wants them to honor Him with their lives.
You'll find RTR to take a different path in its presentation from anything else out there, as it is unabashedly filled with resources that reference the Bible and that are written from a Christian perspective. God's word is at the heart of each HOD guide, and RTR is no exception!
Blessings,
Carrie