1) There is Salvation in His Name only:

“And there is salvation in no one else; for there is no other name under heaven that has been given among men by which we must be saved.” (Acts 4:12)

2) What is His Name?

“And behold, you will conceive in your womb and bear a son, and you shall name Him Jesus. He will be great and will be called the Son of the Most High; and the Lord God will give Him the throne of His father David; and He will reign over the house of Jacob to the ages, and His kingdom will have no end.” – Angel Gabriel (Luke 1:31 – 33)

3) All who call out to Him (in Truth, at their appointed times of repentance) ‘will be saved’.

“And everyone who calls on the name of the Lord will be saved.” – apostle Peter (Acts 2:21)

“For there is no difference between Jew and Gentile—the same Lord is Lord of all and richly blesses all who call on Him, for, Everyone who calls on the Name of the Lord will be saved.” – apostle Paul (Romans 10:12 – 13)

4) Beyond this ‘temporal life’ (here on earth), “His Name” can “Save” even beyond ‘time & space’ (“no” limits including Hell etc… in the “spiritual realm” with ‘salvation’ coming out of “Zion”, representing the spiritual dwelling of the Most High God) as these two mysterious prophecies echo this ‘truth’ of Saving done by God ‘even’ beyond this life “by His Name”:

“And it will come about that whoever calls on the name of the LORD Will be delivered; For on Mount Zion and in Jerusalem, there will be those who escape, As the LORD has said, even among the survivors whom the LORD calls.” – prophet Joel (Joel 2:32)

“Therefore wait for Me,”

declares the Lord,

“for the day I will stand up to testify.

I have decided to assemble the nations,

to gather the kingdoms

and to pour out My wrath on them—

all My fierce anger.

The whole world will be consumed

by the fire of My jealous anger. Then I will purify the lips of the peoples, that all of them may call on the Name of the Lord and serve Him shoulder to shoulder.” – prophet Zephaniah (Zephaniah 3:8 – 9)

5) In His Name, ‘universal salvation’ will be achieved when ‘each creature’ willingly declares that ‘Jesus Christ is Lord’ when they obtain ‘their Salvation’ in Him:

Condition (such a declaration is only possible by His Holy Spirit —> God doesn’t accept ‘forced/fake’ confessions):

“Therefore I want you to know that no one who is speaking by the Spirit of God says, “Jesus be cursed,” and no one can say, “Jesus is Lord,” except by the Holy Spirit.” – apostle Paul (1 Corinthians 12:3)

For the ‘Salvation of every creature’ (to ‘His Glory’):

“For this reason also, God highly exalted Him, and bestowed on Him the name which is above every name, so that at the name of Jesus every knee will bow, of those who are in heaven and on earth and under the earth, and that every tongue will confess that Jesus Christ is Lord, to the glory of God the Father.” (Philippians 2:9 – 11)

Yes, the ‘bowing of every knee’ and the ‘oath of allegiance to Him’ by declaring that ‘Jesus is Lord’ is ‘Salvation’ (being “saved”) as its Old Testament counterpart of this “same” prophecy reveals:

“Turn to Me and be saved, all the ends of the earth; For I am God, and there is no other. I have sworn by Myself, The Word has gone forth from My mouth in righteousness And will not turn back, That to Me every knee will bow, every tongue will swear allegiance.” – God (Isaiah 45:22 – 23)

P/S:

This ‘last point with verses’ (No. 5 above) itself proves “Universal Salvation” in Christ Jesus our Blessed Lord and Saviour.

That’s why we “preach”:

“How, then, can they call on the one they have not believed in? And how can they believe in the one of whom they have not heard? And how can they hear without someone preaching to them?” (Romans 10:14)

“And how can anyone preach unless they are sent? As it is written: “How beautiful are the feet of those who bring good news!”” (Romans 10:15)

The ‘sounds’ of this Greatest News about God has been ‘sent to the ends of the world’ (including the “spirit world” I believe):

“But I say, didn’t they hear? Yes, most certainly, “Their sound went out into all the earth, their words to the ends of the world.” (Romans 10:18)

A point to ‘ponder’:

“And Isaiah boldly says, “I (God) was found by those who did not seek Me; I revealed Myself to those who did not ask for Me.” (Romans 10:20)

‘Blessed Saviour of the World’