Later through Paul, gentiles were grafted on to the vine. Much later the Roman "church" was created in 325CE Sorry; the first followers of Yah'shua were Messianic Jews.
shalom b'SHEM Yah'shua HaMashiach
by the pagan, Constantine.
It is true that they were Jews. It is true they believed Jesus of Nazareth was the Messiah.
However, they never called themselves "messianic Jews." Others called them "Christians". Throughout the New Testament, Paul referred to them as believers, brothers, etc. Not once did he say "Messianics."
That is a far more recent name. It's a name I have no problem with in terms of a group providing itself a name that also offers an explanation of its positions. There is much about the Messianics that I've run across that is admirable. IMHO, they need to work a bit more on how they explain their Trinitarian views -- because they do appear Trinitarian to me -- but they get there by a circuitous biblical logic that makes the head spin.
*8the first followers of Yah’shua were Messianic Jews.**
And they went to synagogue on Saturday and then they celebrated the Eucharist on Sundays in house churches.