The Pillars of the Earth by Ken Follett
This is a long book, roughly 1,000 pages. I know what you're thinking: 1,000 pages! There's no way I'd read that. Hold on. It's not a difficult read, and it's incredibly interesting. The book spans decades, and the plot is centered around the building of a cathedral in 12th century England. The story is told from the perspectives of many different people somehow involved with the cathedral... the master builder of the cathedral, the head monk at the monastery that's building the cathedral, the earl of a nearby province, and the wool merchant that lives in the village of the cathedral - to name a few.
What is probably most shocking to some is that the author of this cathedral book that includes multiple figures from the Catholic church is an atheist. It is very subtle ribbon that you can see throughout the book though. But only if you're looking for it. More often than not the religious characters are ambitious and greedy and sometimes narrow-minded, while the master builder and wool merchant simply want to be happy and loved.
The real test is would I read this book again? Absolutely. I enjoy stories that take decades to tell and are told from different perspectives. So if you like books that are really more a saga than a single story, cathedrals or the Thomas Becket-era of England, I strongly urge you to give this one a try.