"In 1920 parent-controlled schools of Reformed or Calvinistic persuasion were brought together in the National Union of Christian Schools. The purposes of the Union as set forth in its constitution are: to establish normal schools and to write textbooks; to maintain a school magazine; to raise the standard of education; to keep salaries of teachers adequate; to maintain a teacher's agency; to seek uniformity in teacher appointments; and to propagate Christian Education, especially through the conferences and conventions.
The basis of the doctrinal position of the Union is the Reformed or Calvinistic world and life view. These are its principles: all life and all instruction should be God-centered; man, created in God's image, must think God's thoughts after Him; man has dominion over all creation; in Adam all men sinned and so live apart from God; through Christ, man is a new creation, but sinful ways still cling to him; all believers are supplied with an adequate knowledge of God through nature and the Bible; education is redemptive, a bringing into conscious subjection to God what has been redeemed in Christ.
Organizers of the Union enunciated four principles in their insistence upon parent-society control of education: God makes parents responsible for the training of their offspring; this responsibility must be borne personally or in union with other persons having the same responsibility, apart from any intermediary, be it church or state; neither the state nor the church is qualified to give rounded instruction to children-the former in this country, must not have anything to do with religion, the latter concerned fundamentally with spiritual work, cannot prepare youth for temporal life; the parent-society-operated school may have the aid and the interest of the church, but the church should not dominate the school, for a school board charged with the task of managing the school is the proper agency. In 1960 the National Union of Christian Schools had 233 member schools with an enrollment of 57,310 pupils."
Excerpt from History of Christian Education by C.B. Eavey