A Christian school is a school run on Christian principles or by a Christian organization.
The nature of Christian schools varies enormously from country to country, according to the religious, educational, and political cultures. In some countries, there is a strict separation of church and state, so all religious schools are private; in others, there is an established church whose teachings form an integral part of the state-operated educational system; in yet others, the state subsidizes religious schools of various denominations.
In the United States, religion is generally not taught by state-funded educational systems, though schools must allow students wanting to study religion to do so as an extracurricular activity, as they would with any other such activity.
Over 4 million students, about 1 child in 12, attend religious schools, most of them Christian.
There is great variety in the educational and religious philosophies of these schools, as might be expected from the large number of religious denominations in the United States.
The largest system of Christian education in the United States is operated by the Roman Catholic Church. As of 2011[update], there were 6,841 elementary and secondary schools enrolling about 2.2 million students. Most are administered by individual dioceses and parishes.
The Lutheran Church-Missouri Synod (the primary Conservative Lutheran denomination in the US) operates the largest Protestant school system in the United States. Currently the LCMS operates 1,368 Early Childhood Centers, 1,018 elementary schools, 102 high schools, ten universities and two seminaries for a total of 2488 schools in the United States. These schools educate more than 280,000 students and are taught by almost 18,000 teachers. The only state without a Lutheran school is Maine. Lutheran schools operated by the LCMS also exist in Hong Kong and mainland China (2006-2007 school year statistics). The Wisconsin Evangelical Lutheran Synod (WELS) currently operates 23 high schools.