Nazarene vs. Messianic:

Exposing One Faith Two Expression Theology

Most Christians today profess that Sunday is the Sabbath. Others will
say that the Sabbath has been done away with and replaced by Sunday
“the Lord’s Day” as the day of worship for the “Church”(1). This belief
has been widely accommodated even in the mainline of the Messianic
Jewish movement. For example regarding Sunday worship Daniel
Juster writes: "...Sabbath is a day of crucial significance to Jewish identity.
The principle of weekly rest, worship and renewal is one
of universal significance. In this sense, the Sabbath principle is a spiritual and humanitarian guide for all peoples.
Christians are free to incorporate this principle on Sunday or other days. The seventh day Sabbath for Israel is
a special central sign of the Covenant between Israel and God."
(Jewish Roots p. 195)