In my previous post I recommended that you read Dee Henderson's O'Malley series, eventhough at that point I had only read the first book in the series.
I have since completed all six books as well as the prequal, and have something very important I would like to add.
What makes the O'Malley series so special is the fact that it deals with legitimate concerns non-believers might have. The series questions things like why bad things sometimes happen to good people, why all prayers aren't answered, how Jesus could have been ressurected from death after three days, and why an all powerful God would like to have a personal relationship with sinners, to name but a few.
If you have friends who are struggling with the Christian faith, these books can shed a light on how you can approach their concerns. It even highlights some bible verses you can use to answer some of these questions!
These books would be a wonderful gift to Christians, old and new!