Why shouldn't Sunday be called the Sabbath?
Sunday should not be called the Sabbath because the biblical Sabbath is the seventh day, instituted by God for Israel and written into the Ten Commandments. Sunday is the first day of the week and is associated with Christ's resurrection, the high point of God's dealing with man and the basis for believers after His resurrection.
Les explains that the Sabbath was instituted before the Ten Commandments were given, when God mandated Israel to keep the seventh day as a holy day of rest and worship, and He later incorporated it into the Ten Commandments. That Sabbath is specifically the seventh day. Sunday, however, is the first day of the week, not the seventh. Les points to the resurrection of Christ as the very epitome and high point of all God's dealing with man, and believers today have become believers after His resurrection. Therefore, calling Sunday the Sabbath confuses Israel's seventh-day Sabbath with the first-day celebration of resurrection life and the Church age. For over 20 years Les instructed his classes never to call Sunday the Sabbath, because Sunday is not a Sabbath.