The question is whether the weekly Sabbath comes within the scope of the distinction respecting days on which the apostle reflects in Romans 14:5. If so then we have to reckon with the following implications:
This would mean that the Sabbath commandment in the Decalogue does not continue to have any binding obligation upon believers in the New Testament economy. The observance of one day in seven as holy and invested with the sanctity enunciated in the fourth commandment would be abrogated and would be in the same category in respect of observance as the ceremonial rites of the Mosaic institution. On the assumption posited, insistence upon the continued sanctity of each recurring seventh day would be as Judaizing as to demand the perpetuation of the Levitical feasts.
The first day of the week would have no prescribed religious significance. It would not be distinguished from any other day as the memorial of Christ's resurrection and could not properly be regarded as the Lord's day in distinction from the way in which every day is to be lived in devotion to and the service of the Lord Christ. Neither might any other day, weekly or otherwise, be regarded as set apart with this religious significance.
Observance of a weekly Sabbath or of a day commemorating our Lord's resurrection would be a feature of the person weak in faith and in this case he would be weak in faith because he had not yet attained to the understanding that in the Christian institution all days are in the same category. Just as one weak Christian fails to recognize that all kinds of food are clean, so another, or perchance the same person, would fail to esteem every day alike.
These implications of the thesis in question cannot be avoided. We may now proceed to examine them in the light of the considerations which Scripture as a whole provides.
The Sabbath institution is a creation ordinance. It did not begin to have relevance at Sinai when the Ten Commandments were given to Moses on two tables (cf. Genesis 2:2-3; Exodus 16:21–23). It was, however, incorporated in the law promulgated at Sinai and this we would expect in view of its significance and purpose as enunciated in Genesis 2:2-3. It is so embedded in this covenant law that to regard it as of different character from its context in respect of abiding relevance goes counter to the unity and basic significance of what was inscribed on the two tables. Our Lord Himself tells us of its purpose and claims it for His messianic Lordship (Mark 2:28). The thesis we are now considering would have to assume that the pattern provided by God Himself (Genesis 2:2-3) in the work of creation (cf. also Exodus 20:11; 31:17) has no longer any relevance for the regulation of man's life on earth, that only nine of the ten words of the Decalogue have authority for Christians, that the beneficent design contemplated in the original institution (Mark 2:28) has no application under the gospel, and that the lordship Christ exercised over the Sabbath was for the purpose of abolishing it as an institution to be observed. These are the necessary conclusions to be drawn from the assumption in question. There is no evidence to support any of these conclusions, and, when they are combined and their cumulative force frankly weighed, it is then that the whole analogy of Scripture is shown to be contradicted by the assumption concerned.
The first day of the week as the day on which Jesus rose from the dead (Matthew 28:1; Mark 16:2, 9; Luke 24:1; John 20:1, 19) is recognized in the New Testament as having a significance derived from this fact of Jesus' resurrection (Acts 20:7; 1 Corinthians 16:2) and this is the reason why John speaks of it as the Lord's day (Revelation 1:10). It is the one day of the week to which belongs this distinctive religious significance. Since it occurs every seventh day, it is a perpetually recurring memorial with religious intent and character proportionate to the place which Jesus' resurrection occupies in the accomplishment of redemption. The two pivotal events in this accomplishment are the death and resurrection of Christ and the two memorial ordinances of the New Testament institution are the Lord's supper and the Lord's day, the one memorializing Jesus' death and the other His resurrection. If Paul in Romans 14:5 implies that all distinctions of days have been obliterated, then there is no room for the distinctive significance of the first day of the week as the Lord's day. The evidence supporting the memorial character of the first day is not to be controverted and, consequently, in this respect also the assumption in question cannot be entertained, namely, that all religious distinction of days is completely abrogated in the Christian economy.
In accord with the analogy of Scripture and particularly the teaching of Paul, Romans 14:5 can properly be regarded as referring to the ceremonial holy days of the Levitical institution. The obligation to observe these is clearly abrogated in the New Testament. They have no longer relevance or sanction and the situation described in Romans 14:5 perfectly accords with what Paul would say with reference to religious scrupulosity or the absence of such regarding these days. Paul was not insistent upon the discontinuance of ritual observances of the Levitical ordinances as long as the observance was merely one of religious custom and not compromising the gospel (cf. Acts 18:18, 21; 21:20–27). He himself circumcised Timothy from considerations of expediency. But in a different situation he could write: "Behold, I Paul say unto you, that if ye be circumcised, Christ will profit you nothing" (Galatians 5:2). Ceremonial feast days fall into the category of which the apostle could say: "One man esteemeth one day above another: another esteemeth every day alike" (Romans 14:5). Many Jews would not yet have understood all the implications of the gospel and had still a scrupulous regard for these Mosaic ordinances. Of such scruples we know Paul to have been thoroughly tolerant and they fit the precise terms of the text in question. There is no need to posit anything that goes beyond such observances. To place the Lord's day and the weekly Sabbath in the same category is not only beyond the warrant of exegetical requirements but brings us into conflict with principles that are embedded in the total witness of Scripture. An interpretation that involves such contradiction cannot be adopted. Thus the abiding sanctity of each recurring seventh day as the memorial of God's rest in creation and of Christ's exaltation in His resurrection is not to be regarded as in any way impaired by Romans 14:5.
John Murray, The Epistle to the Romans, vol. 2, The New International Commentary on the Old and New Testament (Grand Rapids, MI: Wm. B. Eerdmans Publishing Co., 1968), 257–259.