While we are not Christians, I have found the education offered through Rod & Staff to be exceptional.
I started with "First Language Lessons," by Jesse Wise & Sara Buffington. When we finished the fourth level, she suggested continuing with "Rod & Staff." Fantastic discovery for us. Tests, assignments, oral, and written exercises; just add up to the total learning package.
If you're not Christian, and you can get over that hump with an open-mind; there is so much to learn and gain for your child in Rod and Staff.