My study of religious History did not reveal Christians holding a "sabbath" day as a special day to meet for worship. However, History does show that early Jewish Christians continued to assemble on the Sabbath. I imagine that there may have been many arguments about it by Jewish Christians and non-Jewish Christians. But, suffice to say, 99% of the writings of early Christians record that the first day of the week was the day they met to worship and partake of the Lord's supper.
The Gospels do not mention anything about the first day of the week for worship, period. The Gospels closed at the death, burial and resurrection of Jesus. The subject was not considered before the "Church" was started on Pentecost. It was the introduction of the Gospel to the Gentiles when the first day of the week was chosen to be the day for meeting together for worship, "communion or the Lord's supper", teaching, fellowship and exhortation to grow in the knowledge of Christ. I don't see anything in the letters of the NT to indicate that Christians should set aside a Sabbath for meeting together for worship, etc. What you say is not all that clear - it is a mix of opinion and parts of Scripture IMHO.
Paul, in Romans 14:1-8, reveals some very interesting insight into this subject - especially verse 5! "One man considers one day more sacred than another; another man considers every day alike. Each one should be fully convinced in his own mind." As I stated before, let me back it up with what Paul has to say (Verse 4): "Who are you to judge someone else's servant? to his own master he stands or falls. And he will stand, for the Lord is able to make him stand."
To me, those two verses sum up Paul's exhortation on the keeping of a special day or on not keeping a special day set aside for assembling together for worship, etc. If you notice, I did not put my opinions in those verses - I just let them speak for themself. However, if you want to keep a Sabbath day as the day you meet together with others of the same mind, I have no problem with that, and praise you for continuing in living your life for the Lord. The same would apply if you chose not to eat meat, or if you chose to eat only vegetables. Consider that.
Your writing shows you have faith...keep it strong!
Before I step off my last Scripture reference, Acts 20:7 I must say I expressed the Perfect-Participle connotation of the Greek ‘synehgmenohn’ not that well. ‘Having been assembling’ doesn’t make good sense. There seems to be conflict between the Passive and the Active ‘feel about’ the term. Maybe I should have said ‘having had assembling’ or ‘having been assembled’, as does Marshall in the Nestle Interlinear NT. However, the idea is as the Grammars say, to convey the idea of the presently ongoing result of a past finished act. I repeat, ‘synehgmenohn’ is NOT the Verb of the sentence and must not be so translated as to replace the true Predicative Verb , “conversed” - ‘dielegeto’.