"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 Christians in the ancient church very soon distinguished the first day of the week, Sunday; however, not as a Sabbath, but as an assembly day of the church, to study the Word of God together, and to celebrate the ordinances one with another: without a shadow of doubt, this took place as early as the first part of the second century."-Bishop GRIMELUND, "History of the Sabbath," page 60.
"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.
"We have seen how gradually the impression of the Jewish Sabbath faded from the mind of the Christian church, and how completely the newer thought underlying the observance of the first day took possession of the church. We have seen that the Christian of the first three centuries never confused one with the other, but for a time celebrated both." The Sunday Problem, a study book by the Lutheran Church (1923) p.36
"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.