The example used of the contradictions between Exodus 20 (The Sabbath Day Instituted) and Romans 14:5 is erroneous and makes no sense.
In Romans 14:5 the subject is vegetarianism and fasting. The Sabbath is not mentioned once. The original Greek says [One judges a day to be above a day; Another judges every day to be alike. Each in his own mind let be fully assured.]
The Apostle Paul was attempting to settle a dispute between those who ate meat and vegetables and those who ate only vegetables. Verse 6 says [He who regards one day as special, does so to the Lord. He who eats meat, eats to the Lord, for he gives thanks to God; And he who abstains does so to the Lord and gives thanks to God. He is also trying to settle the matter of a particular fasting day.
The early Christians in Rome were sometimes afraid to eat meat because it may have been sacrificed in the pagan temples to the Romans gods before it got to the market.
In 1 Corinthians 8 Paul explains the "Eating Food Sacrificed To Idols" problem and tells the folks not to judge anyone for doing that.....in other words, idols are nothing, so what's the big deal. Do what you want, (my interpretation). Still there were people who felt uncomfortable about eating that food...and not knowing if it had been sacrificed, chose to eat only vegetables. Paul said "That's fine too".
In Luke 18:12 Jesus spoke of a Pharisee who claimed to fast twice a week and give 10% of all he got. In Matthew 6:16 Jesus says, [When you fast, do not look somber as the hypocrites do, for they disfigure their faces to show men they are fasting. I tell you the truth, they have received their reward in full.] So.....fasting among the Jews and early Christians, sometimes twice a week, was very common. It was also, according to the Apostle, a disputable matter, [Romans 14:1]
You can go through the entire chapter in the original Greek and not find mention of the word Sabbath. Paul is telling them if they want to fast this day.... or that day, it is up to them. If they want to eat only vegetables.... that is fine too.
Dang, Diego, can't any of these ever be short?
That sure doesn't sound like "confess your sins to us so that we can pay off families and victims to keep our sins hidden."
No. The point to the Romans 14 passage is primarily about people who are "weak in faith" and the obligation of the Christian not to welcome such a person just to have an occasion for "disputes over opinions," as is plain from verse 1. One example about such contentiousness involves dietary concerns, as you have said. But he gives a second example about the dispute over the Lord's Day in verses 5 and 6. At the time, the dispute between the Hebrew Christians and Gentile Christians over which day was to be observed as the Lord's Day was still ongoing. Sure, the Sabbath is not explicitly mentioned, but it is clear enough that that is what is referred to in vv. 5 & 6. St. Paul didn't have to even mention the Sabbath by name, as ALL of his hearers knew quite well what he was talking about.