Plenty of Messianic Jews go to services on Saturday if that's what you are talking about.
It is not REQUIRED for Gentiles to live according to the ceremonial aspects of the Mosaic Law, though.
These include days and dietary laws.
Other elements of the Mosaic Law are moral and nature, and a believer who is being conformed to the image of Jesus would not want to disobey those as they reflect the image of God.
But, believers are not Jews. Judaizers are those that claim this.
They claim that observing ceremonial elements like days and diet are required for the New Covenant believer. Some even go so far as to claim that you need to get your foreskin snipped to be acceptable to God.
Hogwash!
Those individuals are Judaizers and Paul anathematized them in Galatians.
If a Messianic Jew wants to continue observance of days and dietary elements of the Mosaic Covenant, without claiming others are required to observe them, this is fine, but those who claim all must observe them are Judaizers and fall under Paul's anathema.
Such individuals probably don't know Jesus, and thus don't know the Father. They don't believe in justification by faith alone, therefore they are accursed.
This is regardless of how religious they appear, with their external observances. Their heart has not been changed.
What I am talking about? Learning how Christ wants us to live is what I am talking about. The people of The Way lived at a time that some of them knew Christ as the man who lived on this earth, I think learning how they worshiped would be enlightening.
You seem to think that the difference in our worship today from them is that they followed Judaism practices, and we are told not to. You are including everything that applies to dates of the year to those practices. I think we should question that. We use dates of the years in our current worship practice like December 25 yet we call their using dates Judaism.
We have little information about this church of Christ called The Way. I have found lots of what the gentile leaders of the Christian church wrote about, but little about The Way. I did read a copy of a report given to a Roman Emperor (before 325) that said the members of the new sect loved and cared for each other and were not only harmless to Rome but admirable people.
The Messianic Church started after the dead sea scrolls were discovered. These scrolls gave information about the people of the bible and their culture that opened up understanding of scripture that had been lost. Through the writings found there the languages were found and what Hebrew words meant to them at that time. I haven't heard of any Messianic who uses Judaism. They believe in scripture, all of it, and study of scripture is their goal. You cannot believe in scripture and believe in such as circumcision. However, it is possible to believe in scripture and question tossing out Passover, the Sabbath, and all dates. Only a certain interpretation of one scripture backs up this practice, and that is relating to judging.
You are right, according to Luke many of the first Christians believed in Judaism practices, and scripture tells us that we are not to use these.