I don’t know about that. What support is there for this?
Here’s Isaiah 11:[Isa 11:9 KJV] 9 They shall not hurt nor destroy in all my holy mountain: for the earth shall be full of the knowledge of the LORD, as the waters cover the sea.
Verse 9 does say the earth will be full of the knowledge of God, but it says nothing of everyone acknowledging and serving God. Later, it instead points to more of a political conquest of the Gentile nations.[Isa 11:14 KJV] 14 But they shall fly upon the shoulders of the Philistines toward the west; they shall spoil them of the east together: they shall lay their hand upon Edom and Moab; and the children of Ammon shall obey them.
Here’s Isaiah 40:[Isa 40:5 KJV] 5 And the glory of the LORD shall be revealed, and all flesh shall see [it] together: for the mouth of the LORD hath spoken [it].
Yes, the glory of God will be revealed to all, but it doesn’t say everyone will believe in God.
Here’s Zephaniah 3:[Zep 3:8-9 KJV] 8 Therefore wait ye upon me, saith the LORD, until the day that I rise up to the prey: for my determination [is] to gather the nations, that I may assemble the kingdoms, to pour upon them mine indignation, [even] all my fierce anger: for all the earth shall be devoured with the fire of my jealousy. 9 For then will I turn to the people a pure language, that they may all call upon the name of the LORD, to serve him with one consent.
It’s more like God is pouring out his judgement on the nations rather than a cosmic altar call to the nations.
For then will I turn to the people a pure language, that they may all call upon the name of the LORD, to serve him with one consent.
Depends on who “all” is referring to. As I mentioned, in the preceding verse, there is a judgment against the nations. In the passage after it, Zeph 3:12-20, it is talking about the remnant of Israel.[Zep 3:12-13 KJV] 12 I will also leave in the midst of thee an afflicted and poor people, and they shall trust in the name of the LORD. 13 The remnant of Israel shall not do iniquity, nor speak lies; neither shall a deceitful tongue be found in their mouth: for they shall feed and lie down, and none shall make [them] afraid.