Seventh-day Adventist doctrine on the presumed sanctity of Sunday as the Christian Sabbath is cited here: A Quick History of the Apostasy of the Christian Church and The Seven Distinct Periods of Church History.

Ellen G. White wrote:

The spirit of concession to paganism opened the way for a still further disregard of Heaven's authority. Satan, working through unconsecrated leaders of the church, tampered with the fourth commandment also, and essayed to set aside the ancient Sabbath, the day which God had blessed and sanctified (Genesis 2:2, 3), and in its stead to exalt the festival observed by the heathen as "the venerable day of the sun." This change was not at first attempted openly. In the first centuries the true Sabbath had been kept by all Christians. They were jealous for the honor of God, and, believing that His law is immutable, they zealously guarded the sacredness of its precepts. But with great subtlety Satan worked through his agents to bring about his object. That the attention of the people might be called to the Sunday, it was made a festival in honor of the resurrection of Christ. Religious services were held upon it; yet it was regarded as a day of recreation, the Sabbath being still sacredly observed. {GC 52.1}

No law has ever been made to exalt the idol sabbath but that Satan has taken a leading part in its enactment and its enforcement. Every law for the elevation of Sunday has a direct reference to the fourth commandment. Every move that has been made to enforce its observance, is for the purpose of exalting the man of sin above God and above all that is worshiped. Satan would have us exalt the idol sabbath, but we cannot do it, for it would be disloyalty to God. {RH, April 29, 1890 par. 9}

http://everythingimportant.org/triviality