***In the millennial reign, the coming kingdom, Sabbath's shall be reestablished
Isaiah 66:20-23
King James Version
20 And they shall bring all your brethren for an offering unto the Lord out of all nations upon horses, and in chariots, and in litters, and upon mules, and upon swift beasts, to my holy mountain Jerusalem, saith the Lord, as the children of Israel bring an offering in a clean vessel into the house of the Lord.
21 And I will also take of them for priests and for Levites, saith the Lord.
22 For as the new heavens and the new earth, which I will make, shall remain before me, saith the Lord, so shall your seed and your name remain.
23 And it shall come to pass, that from one new moon to another, and from one sabbath to another, shall all flesh come to worship before me, saith the Lord.
***In the coming kingdom, festivals shall be reestablished
Zechariah 14:16-19
16 And it shall come to pass, that every one that is left of all the nations which came against Jerusalem shall even go up from year to year to worship the King, the Lord of hosts, and to keep the feast of tabernacles.
17 And it shall be, that whoso will not come up of all the families of the earth unto Jerusalem to worship the King, the Lord of hosts, even upon them shall be no rain.
18 And if the family of Egypt go not up, and come not, that have no rain; there shall be the plague, wherewith the Lord will smite the heathen that come not up to keep the feast of tabernacles.
19 This shall be the punishment of Egypt, and the punishment of all nations that come not up to keep the feast of tabernacles.