“ And the third angel followed them, saying with a loud voice, If any man worship the beast and his image, and receive his mark in his forehead, or in his hand, The same shall drink of the wine of the wrath of God, which is poured out without mixture into the cup of his indignation; and he shall be tormented with fire and brimstone in the presence of the holy angels, and in the presence of the Lamb: And the smoke of their torment ascendeth up for ever and ever: and they have no rest day nor night, who worship the beast and his image, and whosoever receiveth the mark of his name. Here is the patience of the saints: here are they that keep the commandments of God, and the faith of Jesus.”
Revelation 14:9-12
What does the Bible say about rest?
Let us therefore fear, lest, a promise being left us of entering into his rest, any of you should seem to come short of it. For unto us was the gospel preached, as well as unto them: but the word preached did not profit them, not being mixed with faith in them that heard it. For we which have believed do enter into rest, as he said, As I have sworn in my wrath, if they shall enter into my rest: although the works were finished from the foundation of the world. For he spake in a certain place of the seventh day on this wise, And God did rest the seventh day from all his works. And in this place again, If they shall enter into my rest. ” Hebrews 4:1-5
This takes us to the creation account:
“And on the seventh day God ended his work which He had made; and He rested on the seventh day from all his work which He had made.”
Genesis 2:2
So we find how God gave us the example of a weekly rest on the Sabbath.
He gave it to Adam as a day of rest. It was a memorial of the work of creation, and thus a sign of God's power and His love. ” The Desire of Ages (DA 281.2)
This brings us to the 4th Commandment:
“For in six days the Lord made heaven and earth, the sea, and all that in them is, and rested the seventh day: wherefore the Lord blessed the sabbath day, and hallowed it.”
Exodus 20:11
We find how God uses the Sabbath "rest" as a test of loyalty.
“And hallow my sabbaths; and they shall be a sign between me and you, that ye may know that I am the Lord your God.”
Ezekiel 20:20
The Sabbath rest is a sign of allegiance.
“By observing the true Sabbath Christians are ever to bear to the world faithful witness of their knowledge of the true and living God as distinguished from all false gods, for the Lord of the Sabbath is the Creator of the heavens and the earth, the One exalted above all other gods.”
Selected Messages Book 3 (3SM 256.1)
It is a way to distinguish from false gods.
To show who we worship will be largely based on which day we worship.
“When our nation, in its legislative councils, shall enact laws to bind the consciences of men in regard to their religious privileges, enforcing Sunday observance, and bringing oppressive power to bear against those who keep the seventh-day Sabbath, the law of God will, to all intents and purposes, be made void in our land, and national apostasy will be followed by national ruin.”
The S.D.A. Bible Commentary 7:977 1888 (LDE 133.5)
“Roman Catholic principles will be taken under the care and protection of the state. This national apostasy will speedily be followed by national ruin.”
The Review and Herald (RH June 15, 1897)
“When Protestant churches shall unite with the secular power to sustain a false religion, for opposing which their ancestors endured the fiercest persecution, then will the papal sabbath be enforced by the combined authority of church and state. There will be a national apostasy, which will end only in national ruin.”
Evangelism, 235 (1899)
“When the state shall use its power to enforce the decrees and sustain the institutions of the church—then will Protestant America have formed an image to the papacy, and there will be a national apostasy which will end only in national ruin.”
The S.D.A. Bible Commentary 7:976 (1910)
So those without "rest" are those who are not obeying God. We must keep all of God's commandments to prove our loyalty and show our desire for harmony. This is only truly possible through faith, specifically the Faith of Jesus.