Romans 14:5
One person considers one day to be above another day. Someone else considers every day to be the same. Each one must be fully convinced in his own mind.
You keep using that verse. I do not think it means what you think it means.
What's more likely? That Paul, by his one sentence, overturned a scriptural commandment of God about the sabbath? A commandment that was 1 of 10 that was written in stone. A commandment that was reiterated over and over and over again in scripture. A commandment that when broken was linked to the downfall of Israel again and again and again. A commandment that had been observed and ingrained into all aspects of Jewish society.
You're taking your desire to worship on Sunday and applying it out of context to a verse that has nothing to do with the sabbath. And it's demonstrable.
1. The verse never mentions the sabbath or holy days.
2. In the broader context of the verse it's clear that the primary focus of these "days" has something to do with eating.
Read Romans 14 for yourself.