1. Has Sabbath observance always been a sign of true believers? - Genesis says nothing about Adam and Eve “resting” with God on the first seventh day. It says only that God rested. While it is certainly possible that Sabbath was observed by believers before the Exodus, there is no direct Biblical evidence that Adam, or Eve, or anyone else participated in rest on the seventh day of creation until at least 2,600 years had passed and the Israelites had left Egypt.
Pastor Sydney Cleveland writes:
Contrary to Sabbatarian assertions, the Bible is completely silent upon the subject of the “Sabbath” until the time of the Exodus. In fact, the word “Sabbath” is not even mentioned in the Bible until 2,600 years after Creation week. Check your Bible Concordance and you will discover the Hebrew word for “rest” (“Shabbat”/Sabbath – in the sense of resting from one’s work) is not mentioned until the Exodus, 2,600 years after Creation!
God had laws which Abraham obeyed (Gen. 26:5), and most of the Ten Commandments are mentioned in one or more places in Genesis, but the Sabbath is never mentioned after the creation week.
Since Abraham kept God's laws, one could assume he and his descendents kept the Sabbath. If so, the Sabbath could have been lost during Israel's long years of slavery in Egypt when they were most likely required to work every day of the week. The first explicit mention of Sabbath observance dates from approximately 1450 B.C. at the time when manna was given in the desert of Sinai. Shortly afterwards, God made the Sabbath regulation known to the Israelites when He gave them the Old Covenant:
You came down on Mount Sinai...You made known to them (Israelites) your holy Sabbath and gave them commands, decrees and laws through your servant Moses. (Neh. 9:13-14)
While the Israelites may have had some prior understanding of the importance of the Sabbath based upon the God's provision of the manna on six days of the week, they most likely did not fully understand it until the giving of the law on Mount Sinai.
There is no historical or anthropological evidence that Noah or his descendents kept a Sabbath or even a weekly cycle. The only ancient culture to observe a seven-day week were the Sumerians, who started the practice around 2,350 BC:
Sargon I, King of Akkad, having conquered Ur and the other cities of Sumeria, then instituted a seven-day week, the first to be recorded. ... They worshipped seven gods whom they could see in the sky. Reverently, they named the days of their week for these seven heavenly bodies.8
The Sumerian institution of a seven-day week had nothing to do with the creation week, but was in honor of their seven astronomical gods. Dr. Russell Kelley notes, "The frequency of market days, not an innate call to worship on the seventh-day Sabbath, determined the amount of days in a 'week' for ancient civilizations."9
- Some tribes in West Africa adopted four-day intervals between market days.10
- The Assyrians adopted five-day intervals.11
- Ancient Rome adopted eight-day intervals.12
- Ancient Egyptians adopted ten-day intervals.13
- The Mayans, Aztecs, and Toltecs used a 13-day or 20-day weekly cycle.14
- It was not until the first century B.C. that Rome adopted the seven-day weekly cycle.15
The idea that the followers of God prior to the Exodus kept the Sabbath, or even a weekly cycle, is not explicitly stated anywhere in Scripture or history. While it is possible Abraham and other early believers kept the Sabbath, there is no direct Biblical evidence to prove such. Adventists must make up for the lack of Biblical proof by relying on their inspired prophet, Ellen G. White.
2. Is the Sabbath still a "sign" between God and His People? Under the covenant agreements that God made with Abraham and the Israelites, several practices were instituted by God as signs of obedience which the Israelites were expected to follow for all their generations.
The first was Circumcision (Gen. 17:9-14)....
And God said unto Abraham, Thou shalt keep my covenant therefore, thou, and thy seed after thee in their generations. This [is] my covenant, which ye shall keep, between me and you and thy seed after thee; Every man child among you shall be circumcised.....and it shall be a token of the covenant betwixt me and you...and my covenant shall be in your flesh for an everlasting covenant....
...and second was the Passover (Ex. 12:13-14)....
And the blood shall be to you for a token upon the houses where ye [are]: and when I see the blood, I will pass over you, and the plague shall not be upon you to destroy [you], when I smite the land of Egypt. And this day shall be unto you for a memorial; and ye shall keep it a feast to the LORD throughout your generations; ye shall keep it a feast by an ordinance for ever.
...and the third was Sabbath observance (Ex. 31:13,17)....
But as for you, speak to the sons of Israel, saying, You shall surely observe my sabbaths: for this is a sign between me and you throughout your generations, that you may know that I am the Lord that sanctifies you. ...
It [is] a sign between me and the children of Israel for ever: for [in] six days the LORD made heaven and earth, and on the seventh day he rested, and was refreshed.
Notice that the Sabbath as a "sign" was given to the children of Israel. Seventh-day Adventists claim that they are "spiritual Israel". If so, then why do they not also practice the other "eternal signs" of obedience between Israel and God?
Notice that the "signs" of Circumcision and the Passover were to be practiced by God's special people forever. So, why don't Adventists celebrate the Passover? The truth is that the signs of obedience given specifically to Israel, such as Sabbath-keeping, Circumcision, and Passover are never described in the New Testament as signs for Christians living under the New Covenant. While it is certainly appropriate for a Christian to observe the Ten Commandments, including the Sabbath, there is no statement in the New Testament calling the Sabbath a sign of any sort between God and Christians.
The sign of Circumcision and observance of the laws of Moses were an issue in the early church. A church council was convened in Jerusalem around 50 AD and the Apostles debated over which of the laws Moses had written applied to Christians. During that council the brethren settled upon four laws for Gentile converts:
For it seemed good to the Holy Ghost, and to us, to lay upon you no greater burden than these necessary things; That ye  abstain from meats offered to idols, and  from blood, and  from things strangled, and  from fornication: from which if ye keep yourselves, ye shall do well. Fare ye well. (Acts 15:28,29)
Notice that it was the "Holy Ghost" that made these requirements, and the Apostles were careful to say that "no greater burden" from the law of Moses was to be laid upon the Gentiles than these four requirements. In fact, in the same letter, the Church leaders make it clear that they never placed a burden of keeping the Mosaic law upon the Gentile converts:
Forasmuch as we have heard, that certain which went out from us have troubled you with words, subverting your souls, saying, [Ye must] be circumcised, and keep the law: to whom we gave no [such] commandment. (Acts. 15:24)
This verse makes it abundantly clear that the Apostles never commanded their followers to "keep the law" of Moses. In this context, the law refers to all the ordinances and commands written by Moses in the Torah, including the passage where the Sabbath is described as a sign between God and Israel (Ex. 31:13,17). In fact, the Apostles considered that for Christians to attempt to observe the teachings of Moses in the Torah would be tantamount to "subverting your souls." There is no evidence that any of the three signs of Israel (Circumcision, Passover, Sabbath observance) were ever considered "signs" of Christianity.16 On the contrary, Paul fought vigorously against enforcing the sign of circumcision upon gentile converts (see Galatians). Paul said that Christ was the fulfillment of the Passover (1 Cor. 5:7).
Obviously, new converts were expected to follow the moral teachings of Christ which are based upon and expand upon the Ten Commandments and various moral laws in the Torah. However, if Sabbath was indeed the "sign" of Christianity, then we would expect to find some mention of it in the New Testament, but there is none. For the authors of the New Testament to leave out something as fundamental as the "sign" of Christianity would have been a major oversight!
3. Is the Seal of God found in the Ten Commandments? Isaiah 8:6 reads: "Bind up the testimony, seal the law among my disciples." Some Adventists teach the word "law" refers to the Ten Commandments. In reality, the word "law" means the Torah, which refers to the first five books of the Bible, said to be written by Moses. In the Torah there are 613 laws which the Israelites were expected to follow. As noted above, Christians are not required to keep all of the laws of the Torah. This verse has nothing to do with the Seal of God in Revelation.
4. If the Lord's name, title, and dominion appear in a Bible verse, is that passage the Seal of God? Just because a Bible verse mentions the name (YHWH), title (Elohim or Adonay) and dominion of God does not mean that verse is desribing Revelation's "Seal of God". For example, using SDA logic, one could argue that the Torah is the "Seal of God" because it contains this verse:
Behold, the heaven and the heaven of heavens [is] the LORD'S thy God, the earth [also], with all that therein [is]. (Deut. 10:14)
Or one could claim that the prophetic writings of Isaiah or Jeremiah are the "Seal of God" using SDA logic:
O LORD of hosts, God of Israel, that dwellest [between] the cherubims, thou [art] the God, [even] thou alone, of all the kingdoms of the earth: thou hast made heaven and earth. (Isa. 37:16)
Ah Lord GOD! behold, thou hast made the heaven and the earth by thy great power and stretched out arm, [and] there is nothing too hard for thee. (Jer. 32:17)
In addition to the Ten Commandments, look at all of the other Bible verses that mention God's name (God), His title (Lord), and His dominion (heaven and earth):
Gen. 14:22, Gen. 24:3, Deut. 3:24, Deut. 4:39, Deut. 10:14, Jos. 2:11, 1 Ki. 8:23, 2 Ki. 9:15, 2 Chr. 2:12, 2 Chr. 6:14, Isa. 37:16, Jer. 32:17, Acts 4:24, Acts 17:24
It should now be evident that just because God's name, title, and dominion appear within a Bible verse does not prove that passage has any particular connection with Revelation's "Seal of God".
5. Sabbath a Dividing Issue? - Is the Sabbath the great separating truth that will decide who the true believers are? According to the prophet Ellen White, the Sabbath is what separates real believers from false believers:
"I saw that the holy Sabbath is, and will be, the separating wall between the true Israel of God and unbelievers; and that the Sabbath is the great question to unite the hearts of God's dear, waiting saints."17
Such a teaching is contrary to the New Testament. Never is the Sabbath described as a dividing issue by Jesus or the Apostles. Paul wrote:
One man esteemeth one day above another: another esteemeth every day [alike]. Let every man be fully persuaded in his own mind. He that regardeth the day, regardeth [it] unto the Lord; and he that regardeth not the day, to the Lord he doth not regard [it]. (Rom. 14:5,6)
Stop and read Ellen White's quote again, and then read Paul's quote again. The two are completely incompatible!
In Romans 14 Paul goes through a lengthy discussion in which he warns Christians not to judge each other on points of minor importance. He concludes by saying, "Let us not therefore judge one another" (Rom. 14:13). The Adventist will argue that Paul did not have the Sabbath in mind when he wrote Romans 14, and that could well be the case. Nevertheless, if Paul thought the Sabbath was the "dividing wall" between Christians and non-Christians, don't you think he would have fought strenuously for its observance?
Throughout the New Testament Paul fights with all his might to establish the important doctrines of the Church: Faith, Hope, Love, Grace, Forgiveness, Salvation, Mercy. Paul also fights against the sins of the flesh. Paul even advocated cultural practices such as wearing a head-covering. Yet in all of his writings, he never mentions the seventh day Sabbath as being of particular importance to Christians. The only time he ever even mentions holy days (Rom. 14) he simply says that brethren should accept each other no matter what holy day they choose (or choose not) to observe. How could Paul discuss holy days in such a casual manner if it was indeed the great "dividing wall" between true believers and false believers? If it was truly the great "dividing wall", then Paul would have been all over the issue in his writings, warning Christians of their duty! Instead, we find the Sabbath rarely even mentioned by any of the authors of the New Testament. If the Sabbath was indeed the "one great truth" that is to divide the true believers from the false ones, then surely the Apostles, writing under the inspiration of the Holy Ghost, would have emphasized its overwhelming importance in their writings.