I've recently been dialoging with a Sabbatarian who I think if a Messianic Jew. We've been talking about Worshiping on the Sabbath:
I have to correct you on one thing, if I may. To call the Sabbath 'the Jewish Sabbath' is a grievous error. The 'Jews' didn't create or own God's Law, His Word, His Appointed Times, or His Sabbath. They all belong to Yahweh, God of Israel.
"Verily My Sabbaths ye shall keep: for it is a sign between Me and you throughout your generations; that ye may know that I am the Lord that doth sanctify you."—Exodus 31:13.
"Moreover also I gave them My Sabbaths to be a sign between Me and them, that they might know that I am the Lord that sanctify them."—Ezekiel 20:12.
"And hallow My Sabbaths; and they shall be a sign between Me and you, that ye may know that I am the Lord your God."—Ezekiel 20:20.
So it seems we have God's Sabbath and the Catholic Church's Sabbath.
I have to applaud your usage of 'the 8th day', but allow me to shine further light on it, if you will.
Lets look at Leviticus 23. It starts with Yahweh, God of Israel giving His Appointed Times. Notice in verse 2 that they are HIS, not the Jews. Then we see another proof that the Sabbath belongs to Yahweh, not the Jews in the following verse (verse 3). Let's fast forward though to verse 36, where we get to the part about 'the 8th day'.
Seven days ye shall offer an offering made by fire unto the LORD: on the eighth day shall be an holy convocation unto you; and ye shall offer an offering made by fire unto the LORD: it is a solemn assembly; and ye shall do no servile work therein.
Here's one of the original reference to the great 8th day. The first day following the feast of Tabernacles.
And again in verse 39:
Also in the fifteenth day of the seventh month, when ye have gathered in the fruit of the land, ye shall keep a feast unto the LORD seven days: on the first day shall be a sabbath, and on the eighth day shall be a sabbath.
(and on a side note, verse 41)
And ye shall keep it a feast unto the LORD seven days in the year. It shall be a statute for ever in your generations: ye shall celebrate it in the seventh month.
When "Forever" is spoken by the Creator of all things, we should pay attention.
At any rate, this great 8th day is a celebration, immediately following the Feast of Tabernacles. What it symbolizes is eternity.. the day that never ends immediately following what? Immediately following the Sabbath or the 7th day, or the last 1000 years (see a day is as 1000 years unto the Lord.. the Sabbath is the last 1000 years of man or essentially after 6000 years until 7000 years). What do we also know this as? The Millennial Reign of Messiah! How glorious it will be! But we are not yet there, as we haven't yet entered into that Millennial Reign. So then the Sabbath is still here until after that Millennial Reign of Messiah is complete, and we enter that great 8th day."
Ultimately, he doesn't seem to recognize the New Covenant nor Christ's Victory over Death and the coming of the 8th Day as being present in the Liturgy. Any ideas how I might go about this?