It can be seen in Revelation 18: 4 and 23 that the light can “Go out” among those people who once Heard God’s voice.
Re 18:4 And I heard another voice from heaven, saying, Come out of her, my people, that ye be not partakers of her sins, and that ye receive not of her plagues.
Jesus calls His people to come out of Babylon because eventually the light and voice of God are not heard there.
These people comprise the group referred to as the “Bridegroom” who lived in “Babylon”.
Re 18:23 And the light of a candle shall shine no more at all in thee; and the voice of the bridegroom and of the bride shall be heard no more at all in thee: for thy merchants were the great men of the earth; for by thy sorceries were all nations deceived.
This corresponds to Jeremiah 51:37, and the condition of “Living in Babylon” is what Jesus calls His followers out of in Rev 18:4.
Jer 51:37 And Babylon shall become heaps, a dwelling place for dragons, an astonishment, and a hissing, without an inhabitant.
Re 18:4 And I heard another voice from heaven, saying, Come out of her, my people, that ye be not partakers of her sins, and that ye receive not of her plagues.
So in the case of these verses, two possibilities exist.
Either all of God’s people are obedient and leave Babylon, or some people who were formally Christians stay in Babylon and become unbelievers.
Jer 51:57 And I will make drunk her (Babylon’s) princes, and her wise men, her captains, and her rulers, and her mighty men: and they shall sleep a perpetual sleep, and not wake, saith the King, whose name is the LORD of hosts.
Jesus saves everyone who comes to Him, but what if a person stops coming to Him?
Re 22:19 And if any man shall take away from the words of the book of this prophecy, God shall take away his part out of the book of life, and out of the holy city, and from the things which are written in this book.
Revelation 22:19 would seem to end the discussion. Would God remove someone from the Book of Life?
Yes, He would.
Romans 11:20 Well; because of unbelief they were broken off, and thou standest by faith. Be not highminded, but fear: 21 For if God spared not the natural branches, take heed lest he also spare not thee.
22 Behold, therefore, the goodness and severity of God: on them which fell, severity; but toward thee, goodness, if thou continue in his goodness: otherwise thou also shalt be cut off. 23 And they also, if they abide not still in unbelief, shall be graffed in: for God is able to graff them in again.
Conclusion – Can Christians lose their salvation – Yes.