“The Sabbath is a public token by which the world may recognize the true and living God.” 5MR 123.2

“The Sabbath is the sign of God; it is the seal of His law. Isaiah 8:16. It is the token of His authority and power. It is a sign whereby we may know that He is God, and therefore it is appropriately said to be placed in the forehead. The worshipers of the beast (Revelation 13) are said to receive his mark in their foreheads or in their hands. As the forehead represents the intellect, the hand represents power, as Psalm 89:48, “Shall he deliver his soul from the hand of the grave?” Compulsory worship is not acceptable to God; His servants are sealed only in their foreheads. But it is acceptable to wicked powers; it has always been craved by the Romish hierarchy. See chapter 25 for proof on the nature of this mark. The sign or seal of God is his Sabbath, and the seal or mark of the beast is in direct opposition to it; it is a counterfeit Sabbath on the “day of the sun.” According to Revelation 14:9-12, they who do not receive the mark of the beast keep the commandments of God; and the Sabbath is in the fourth precept; they keep the Sabbath of the Lord; they have his sign or seal. The importance of this sign is shown in this, that the fourth commandment is the only one in the law which distinguishes the Creator from false gods. Compare Jeremiah 10:10-12; Acts 17:23, 24; Revelation 14:6, 7, etc. and it is that part of his law for keeping which his people will suffer persecution. But when the wrath of God comes upon the persecutors who are found enforcing the sign or mark of the beast, then they will realize the importance of the Sabbath,—the seal of the living God. They who turn away from that which the Lord spoke when his voice shook the earth, will confess their fatal error when his voice shall shake the heavens and the earth. Hebrews 12:25, 26; Joel 3:9-16” The Great Controversy (GC88 691.3)

“All through the week we are to have the Sabbath in mind and be making preparation to keep it according to the commandment. We are not merely to observe the Sabbath as a legal matter. We are to understand its spiritual bearing upon all the transactions of life. All who regard the Sabbath as a sign between them and God, showing that He is the God who sanctifies them, will represent the principles of His government. They will bring into daily practice the laws of His kingdom. Daily it will be their prayer that the sanctification of the Sabbath may rest upon them. Every day they will have the companionship of Christ and will exemplify the perfection of His character. Every day their light will shine forth to others in good works.” Testimonies (6T 353.4)