Many schools try to keep students moving on conveyor belts to good careers. Sure, kids fight in the corridors at some places, terrorizing teachers and each other, but most affluent suburban schools function without regular incidents of this sort. They generally give students the tools to get ahead, and fill their heads with all kinds of information and propaganda.
And yet, much of what happens in school could be summarized in the title of a book by the late Neal Postman about education and other aspects of popular culture: Amusing Ourselves to Death. Many "good" schools typically get kids thinking about everything except what is truly important: our relationship to God. They try to turn kids into happy chimpanzees, capable and desirous of following the rules, grinning and gobbling down the bananas offered as rewards.
Christian schools that are up against top-flight public schools are likely to lose, because they typically don't have as many bananas to offer. Christian schools rarely have expensive but well-oiled bureaucracies. They often don't have the clubs and activities that keep kids busy after school. But they can compete because, apart from learning about God in the context of learning about His creation, all of the bells and whistles are worthless. They may seem pleasant rather than destructive physically, but in the end they are destructive morally and theologically.
Christian schools should teach children to resist superficial happiness, the kind that comes too easily. They should want their graduates to be restless selves rather than diverted selves - to be, as Walker Percy says, dislocated humans rather than happy chimps. They should recognize that a lack of self-esteem can hurt, but unearned self-esteem can hurt even more. They should help students to locate themselves spiritually.
One other thing: Christian schools should teach children that it is good to give and fine to receive. The left wants a world where no one serves anyone else, where people are not dependent on others because they have entitlements from government. But that deprives us of part of our humanity. We begin our lives completely dependent on people. We maintain them with partial dependence. We are always completely dependent on God. Charity and service to others makes us less brutish, more giving. They help us to locate ourselves throughout our lives.