A Classical Christian education will emphasize traditional subjects such as rhetoric.It will also infuse every aspect of its teaching with evangelistic fire and purpose. Religion in a Classical Christian school is not an option any more than it is in a Muslim or Jewish or Roman Catholic school. All these schools can take valuable teaching time to accomplish their missionary objectives because they take no state funds. They basically can march to their own pedagalogical tune as long as their clientele is satisfied that the school is doing a good job.
What about prep schools? Religion for most prep schools is merely one more subject offering on the curriculum menu. That does not mean that religion and spiritual values are not taught. They blend in with the other subject offerings. In most prep schools the emphasis is on AP exam preparation. About 30 American private schools offer the IB program.
How can you measure the academic success of a particular private school? Start by asking where last year's class got accepted. How competitive is the admissions process? While the academic achievement and competitive admissions are not necessarily linked, they do give you an idea of what other parents think about the school.
Private schools don't teach to the test. They teach to prepare their students for serious academic work in college. They also balance academics with athletic and extra-curricular activities thereby teaching the whole child.