"The observance of the Lord's Day (Sunday) is founded not on any command of God, but on the authority of the Church." Augsburg Confession of Faith.
"They [the Catholics] allege the Sabbath changed into Sunday, the Lord's day, contrary to the Decalogue, as it appears, neither is there any example more boasted of than the changing of the Sabbath day. Great, say they, is the power and authority of the church, since it dispensed with one of the Ten Commandments." -Augsburg Confession of Faith, Art. 28, par. 9.
"They [Roman Catholics] allege the change of the Sabbath into the Lord's day, as it seemeth, to the Decalogue [the ten commandments]; and they have no example more in their mouths than they change of the Sabbath. They will needs have the Church's power to be very great, because it hath dispensed with the precept of the Decalogue." The Augsburg Confession, 1530 A.D. (Lutheran), part 2, art 7, in Philip Schaff, the Creeds of Christiandom, 4th Edition, vol 3, p64 [this important statement was made by the Lutherans and written by Melanchthon, only thirteen years after Luther nailed his theses to the door and began the Reformation].
"For up to this day mankind has absolutely trifled with the original and most special revelation of the Holy God, the ten words written upon the tables of the Law from Sinai."-"Crown Theological Library," page I78.
"The festival of Sunday, like all other festivals, was always only a human ordinance."- AUGUSTUS NEANDER, "History of the Christian Religion and Church," Vol. 1, page 186.
"I wonder exceedingly how it came to be imputed to me that I should reject the law of Ten Commandments...Whosoever abrogates the law must of necessity abrogate sin also."-MARTIN LUTHER, Spiritual Antichrist," pages 71, 72.
"But they err in teaching that Sunday has taken the place of the Old Testament Sabbath and therefore must be kept as the seventh day had to be kept by the children of Israel .... These churches err in their teaching, for scripture has in no way ordained the first day of the week in place of the Sabbath. There is simply no law in the New Testament to that effect" John Theodore Mueller, Sabbath or Sunday, pp.15, 16