Rom 14:5 In the same way, some think one day is more holy than another day, while others think every day is alike. You should each be fully convinced that whichever day you choose is acceptable. 6 Those who worship the Lord on a special day do it to honor him. Those who eat any kind of food do so to honor the Lord, since they give thanks to God before eating. And those who refuse to eat certain foods also want to please the Lord and give thanks to God.
Rom 14:14 I am convinced, being fully persuaded in the Lord Jesus, that nothing is unclean in itself. But if anyone regards something as unclean, then for that person it is unclean.
Some Bible translation use vocabulary that makes the text sound as if Paul is talking about the Sabbath and the dietary laws found in Leviticus.
one day is more holy than another day
nothing is unclean in itself
Mainstream theology interprets that Paul endorsed the abolition of the dietary instructions in the Old Testament.
A better translation that respect the original text would say:
esteems a day beyond [an ordinary] day
nothing is common in itself
Just because men deem days special, it does not mean that these are holy in the Biblical sense. Paul never said that nothing was unclean in the Biblical sense. He said: nothing is common. The text seems to talk about abstaining from ordinary food on extraordinary days according to matters of opinion.
"Those who worship the Lord on a special day" -- this phrase is a poor translation, the word "worship" does not appear in the original text. It supplies words to make the reader believe that the context is worshiping on Sabbath.
A better translation would say: Those who estimates a day, do it to (honor) the Lord... This is said in the context of eating or fasting. The Sabbath is never a day of fasting unless is falls on the Atonement day. Therefore, the Sabbath cannot be part of the context of this text.
The Pulpit Commentary has a good commentary of the text: "Verse 5. - One man esteemeth one day above another: another esteemeth every day alike (literally, one judgeth day beyond - or, in comparison with - day: another judgeth every day. For κρίνειν in the sense of "estimate," cf. Acts 13:46; Acts 16:15; Acts 26:8. For sense of παρὰ with accusative, cf. 1:25; Luke 13:2. Days being here only briefly referred to in a chapter the main subject of which is meats, some have supposed fast-days only to be meant; in which case the sense might be that some make it a necessary point of conscience to abstain from food, or from certain kinds of food, on particular days, while others make no such distinction between days as a matter of essential import."
The Greek word for the unclean meats of Leviticus is akáthartos. The word koine (wrongly translated as unclean) means common, which does not mean unclean. Remember that the Pharisees wash their hands to avoid contamination from the gentiles when they eat bread. (Mat 15:2) These prescriptions for eating common food are according the traditions of the elders and not according to the Scriptures.
Mainstream theology interprets that the word common (koine) and unclean (akathartos) are equivalent and that both terms refer to the dietary laws found in Leviticus.
These words are not equivalent. An example is the term koine Greek or common Greek spoken by ordinary people. Koine Greek is not unclean Greek. Koine or common refer to the food preparation.
According to the chapter, the distintinction between these extraordinary days from ordinary days is the abstinence from certain food.
Mainstream theology interprets that there are two separate issues in this chapter: the Sabbath and the unclean food.
Apparently Paul mention briefly the Sabbath (only one verse).
Then he proceed to focus on the dietary laws.
The issue of Romans 14 is about one subject: the abstinence from certain food on certain days in matters of opinion. Pay attention that the question is not clean versus unclean, but meat versus no meat.
Whoever eats meat is in contrast with whoever abstains (Rm 14:6)
One who eats all things in contrast with one who eats herbs (Rm 14:2)
One who eats for the Lord in contrast with one who does not eat for the Lord (Rm 14:6)
All things pure in contrast with [All things] evil (Rm 14:20)
Do the Jews fast or abstain from food on the Sabbath?
No fasting or abstinence on Shabbat, or on any holiday or other festival. Yom Kippur is an exception to this rule.
This issue of abstaining from ordinary food on extraordinary days has nothing to do with Sabbath keeping.
The problem with the all-days-made-equal doctrine is that the same theological arguments against Sabbath keeping should also apply to Sunday. If all the days are equal, why does Christianity exalt Sunday over all the other days of the week? According to this interpretation, the day when Christ resurrected should not be better than the day when Jesus rested on the tomb or the day when Jesus died on the cross. But, Sunday-keeping Churches will try to find arguments to escape from the implications of their own interpretations and this is a bad theology.
Mainstream theology claims that the Christian Church exercised their right to worship on Sunday, because all days are made equal. (Rom 14:5,6)
Exalting a day as the day of the Lord (Rev 1:20) goes against the argument that all days are made equal.
The Expositor's Bible Commentary explains that "the close contextual association with eating suggests that Paul has in mind a special day set apart for observance as a time for feasting or as a time for fasting" (Everett Harrison, 1976, Vol. 10, p. 146)