There's no denying it. You'll be sheltering them from part of secular society. But even Christian adults have been instructed to keep the world at arm's length - to be in it but not of it. How much more should we endeavor to protect our children, most of whom are nowhere near ready to withstand the more sophisticated worldly temptations?
But make no mistake. We haven't bought into the common misconception that Christian schools shield children from every temptation and all exposure to sin. This is not only untrue, it's impossible. Christian schools have the same type of kids non-Christian schools have. Sinners. They're all prone to offensive behaviors such as selfishness, anger, and malicious talk. And no matter where your children attend class, they can hardly escape the worldly influences found in movies, books and television.
The difference in the Christian school is that it can apply the Bible to every instance of sinful thought or action, and with God's help, renew the mind of the child. By doing so, Christians schools have a better chance of helping parents produce adults who have been trained in the fine art of godly living and thinking. And when they finally enter the "real" real world, they'll be much more equipped.
"And do not be conformed to this world, but be transformed by the renewing of your mind, that you may prove what the will of God is, that which is good and acceptable and perfect." (Romans 12:2)