There aren't very many good christian books in our world. Not very many to rely on. But God has led men and woman to be inspired and write good books for us and non-christians to enjoy. I know three really good series of christian books.
The first one is Red Rock Mysteries. It is my favorite of the two and has a lot of action. There are two main characters who's names are Ashley and Bryce. They are twins who are good christians along with their mom. They also have a stepdad and stepsister who are not, unfortunately, christians. The twins solve dangerous mysteries and grow in God every day.
The second you have probably heard of...the Mandie series. It is very good too. It is about a christian girl named Mandie who lives with her uncle and mother in a huge mansion. She also is part Iroquois and has adventures in the Iroquois village, as well as at home. She finds mysteries and adventures with her friends, and sometimes visits different countries with her friends and family. It is much more fun then it sounds, and I recommend it as a series to consider reading.
The third book series you might have heard of. It is called the Sugar Creek Gang. The main character is Bill, who is kind hearted and caring. He is a member of the Sugar Creek Gang along with his pals, who also solve mysteries. Bill has a sister and mom and dad, and lives on a barn. The Sugar Creek Gang has many adventures, and grows closer to God as it go's. I think that, if you try it, you will enjoy this series.
I really like these three children/teen series. I hope you will read some and enjoy (what are some of your favorite christian books? How about you tell me by commenting)!