(Rom 14:1) Him that is weak in the faith receive ye, but not to doubtful disputations.
(Rom 14:2) For one believeth that he may eat all things: another, who is weak, eateth herbs.
(Rom 14:3) Let not him that eateth despise him that eateth not; and let not him which eateth not judge him that eateth: for God hath received him.
(Rom 14:4) Who art thou that judgest another man’s servant? to his own master he standeth or falleth. Yea, he shall be holden up: for God is able to make him stand.
(Rom 14:5) One man esteemeth one day above another: another esteemeth every day alike. Let every man be fully persuaded in his own mind.
(Rom 14:6) 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. He that eateth, eateth to the Lord, for he giveth God thanks; and he that eateth not to the Lord he eateth not, and giveth God thanks.
Romans 14 lists two examples of spiritual weakness – and if you look at the nature of the weaknesses you see that the weakness is in fact clinging to a tangible means of pleasing God – avoiding meats was a special way of obeying God, obtaining righteousness in his sight, and so was the keeping of certain days. Paul tells us that while it may help spiritually those who wish to participate in these spiritual exercises, they are NOT actual means of obtaining righteousness, and those who observe these means are weaker in their faith, yet they do these things unto the Lord. Those who are more mature and can see past these physical attempts to please God are not obliged to keep certain days or avoid meats. Since Paul was writing the epistle to the Romans to a group of mixed Jewish and Gentile Christians where there was a definite problem with trying to make the Gentiles observe Jewish customs (e.g. circumcision and the Sabbath), it would have been highly irresponsible of Paul to say this if he knew that what he was saying was NOT true about the Sabbath – that the Sabbath had to be kept. Obviously, in the absence of any specific command about the Sabbath, we must include the weekly Sabbath in with the days that do not need to be observed by the stronger members of the Church.
The important phrase is “Let every man be fully persuaded in his own mind.” If Christians were expected to observe the Sabbath, Paul would be encouraging them to keep the Sabbath, trying to convince them of a certain point of view, not giving them freedom to do what they feel is right. He would not say that both those who ate meat and those who did not eat meat both gave thanks to God, right alongside saying those who keep the day honour God by doing so, and those who don’t also honour God by not doing so, if the Sabbath were indeed as important as Adventists claim it is.