The Young Wizard Series by Diane Duane
Cover of The Wizard's Dilemma
The first book in Diane Duane's Young Wizard's Series is called So You Want to be a Wizard? These books were published long before Harry Potter and are a completely different kind of wizardry.
There are eight books total, so far. There is Christian symbolism and the wizardry is treated more like a science than just fantasy magic. A very epic and exciting adventure!
If you like fantasy, catastrophic and monumental battles of good vs evil, and intriguing characters these are the books to read!
These books are very realistic alongside their wizard elements. The fifth book The Wizard's Dilemma is the story of the main character's struggle when her mother is diagnosed with cancer. It affected me very personally and emotionally.