This is one of the biggest problems every Christian school (CS) or any institution of any kind faces. In order to stick with the original mission or the schools stronger modified mission the CS must intentionally train new staff, remind former staff, and review its mission / worldview continually. This will naturally be done during accreditation visits but should also be made part of the In-service process and built into the school culture. Students need to have ownership in this as well in order for it really be effective.
We do need to get back to the foundations of why we have and believe in Christian schools. Biblical wisdom must be modeled as well as taught. We as educators must focus on a truly Biblical worldview being instilled into the students – that is ultimate education/ discipleship; “teaching them to observe all things whatsoever I have commanded you” Mt. 28:20. We must produce disciples that can reproduce.
A lot of times children reject the teachings of their parents, churches & Christian schools. I have seen a lot of this, being in administration, through the years. Students graduate from Christian schools and turn their backs almost immediately on God. Some of this may be from seeing the hypocrisy in the Christian leaders’ lives – we can speculate all day; if I knew the answer to this I would dedicate my life exclusively to speaking on this one thought in Christian schools and conventions.