I think that I would have been somewhere between sixteen to nineteen when I read the Trilogy.
I have another recommendation that is rather extremely "Christian" and perhaps even "Charismatic Catholic" in its flavour. I consider that this Trilogy, "The Final Quest", "The Call" and "The Torch and the Sword" by Rick Joyner is a lot like "The Lord of the Rings" except that it is openly "Christian" in its flavour.