The past is a road sign to direct us, not a parking space to repose in. Neither is a subjective illusion. The Western Empire was Christianized by the fifth century. The Reformation ideas sparked remarkable economic growth. The Puritans, by and large, planted Christian civilization in the New World.
Historical progress is real.
History reminds us that history is not ultimate. This is why all materialistic conceptions of history fail to satisfy-they cannot account for the evidence of the suprahistorical, of all that transcends history. The existentialists say history is open-ended. The pietists say history is closed-ended. The reconstructionists say history is God-opened.