Every knee will bow before Jesus Christ, the Great God and Savior (Titus 2:13) and every tongue will confess His name:
But why do you judge your brother? Or why do you show contempt for your brother? For we shall all stand before the judgment seat of Christ. For it is written: As I live, says the Lord, Every knee shall bow to Me, And every tongue shall confess to God. So then each of us shall give account of himself to God (Romans 14:10-12 NKJV).
So why wait until judgement day when it will be too late to obey the Gospel? The Jews were told to do this some seven hundred years prior to when God brought heaven down:
I have sworn by Myself; The word has gone out of My mouth in righteousness, And shall not return, That to Me every knee shall bow, Every tongue shall take an oath. He shall say, Surely in the Lord I have righteousness and strength. To Him men shall come, And all shall be ashamed. Who are incensed against Him? In the Lord all the descendants of Israel shall be justified, and shall glory (Isaiah 45:23-25 NKJV).
To understand God's plan here, we need to go back to Isaiah 44, where He lays out the beginning of His plan:
For I will pour water upon him that is thirsty, and floods upon the dry ground: I will pour my spirit upon thy seed, and my blessing upon thine offspring (Isaiah 44:3 NKJV)
We know that God manifest Himself in the flesh as Jesus Christ (John 1:1,14, 1 Timothy 3:16) so this could happen. Look at what Jesus said to the woman at the well:
Jesus answered and said to her, Whoever drinks of this water will thirst again, but whoever drinks of the water that I shall give him will never thirst. But the water that I shall give him will become in him a fountain of water springing up into everlasting life (John 4:13-14 NKJV).
He also said that this water is actually living and that it is the Holy Ghost:
In the last day, that great day of the feast, Jesus stood and cried, saying, If any man thirst, let him come unto me, and drink. He that believeth on me, as the scripture hath said, out of his belly shall flow rivers of living water. (But this spake he of the Spirit, which they that believe on him should receive: for the Holy Ghost was not yet given; because that Jesus was not yet glorified.) (John 7:37-39).
Then just before the risen Christ ascended to heaven, he told His disciples they would receive this living water, the Holy Ghost, in Jerusalem:
And, being assembled together with them, commanded them that they should not depart from Jerusalem, but wait for the promise of the Father, which, saith he, ye have heard of me. For John truly baptized with water; but ye shall be baptized with the Holy Ghost not many days hence (Acts 1:4-5).
And on the day of Pentecost He poured out the Holy Ghost as promised:
And when the day of Pentecost was fully come, they were all with one accord in one place. And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting. And there appeared unto them cloven tongues like as of fire, and it sat upon each of them. And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance (Acts 2:1-4).
When we read Isaiah 45:1, we see that Isaiah was prophesying that God would use Cyrus, the Persian king, to cause the Jews to return to their homeland. Jeremiah prophesied this event as well (2 Chronicles 36:22-23; Ezra 1:1-11), and from Ezra 3:8 we know the initiation of the rebuilding began (around 536 BC).
In this prophetic chapter, God makes it clear that as the Creator of all, He is not to be questioned with what He was about to do:
Thus says the Lord, The Holy One of Israel, and his Maker: “Ask Me of things to come concerning My sons; And concerning the work of My hands, you command Me. I have made the earth, And created man on it. I—My hands— stretched out the heavens, And all their host I have commanded (Isaiah 45:11-12 NKJV).
So what did He do? He declared that He would bring salvation to all the ends of the earth:
Tell and bring forth your case; Yes, let them take counsel together. Who has declared this from ancient time? Who has told it from that time? Have not I, the Lord? And there is no other God besides Me, A just God and a Savior; There is none besides Me. Look to Me, and be saved, All you ends of the earth! For I am God, and there is no other (Isaiah 45:18-22NKJV).
Here we are at the crux of the matter. God not only gave the Jews the opportunity to be saved, but He has given every single soul on this planet the same opportunity. But here we are, almost 2000 years later and there are billions of lost souls who are missing out on this opportunity to spend eternity on the street of gold (Revelation 21:21) with Jesus.
These same people will say that they don't believe in Jesus, they believe in .... whatever! People never believed or understood gravity either until Newton discovered it in the 17th century. But, obviously, that didn't mean there wasn't gravity.
The same thing will happen when every soul kneels before Jesus and confesses His name. We will see His nail scarred feet and hands and pierced side, just like Thomas did (John 20:27). At that instant the "lost souls" will know they should have taken the opportunity, when they had the chance, to be obedient to the Gospel of Jesus Christ by obeying Acts 2:38. They will be judged severely that day (Matthew 25:31-46).