Romans 14:11

For it is written, As I live, saith the Lord, to me every knee shall bow, And every tongue shall confess to God.

This quotation from Isaiah 45:23 was frequently in the apostle's thoughts, as, for example, when he wrote the Philippians:

In the name of Jesus every knee should bow, of things in heaven, and things on earth, and things under the earth, and that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father (Philippians 2:10,11).

As Lenski truly observed:

In neither Isaiah nor here nor in Philippians (a most pertinent parallel) are "every knee" and "every tongue" restricted to the godly. Paul cites the passage here where he speaks only of Christians; but that means that what the Lord said about every person applies also to every Christian. To bend the knee to God and to confess him signify only that at the time of the last judgment all men shall acknowledge him as God; in more detail, "that Jesus Christ is Lord, to the glory of God the Father."[10]

The composite picture of the final judgment, as gleaned from many scriptures, conclusively shows that infidelity will at last perish in the cataclysmic events of the Second Advent, when Jesus Christ shall suddenly appear with ten thousand of his holy angels to take vengeance upon them that know not God and obey not the gospel of the Lord Jesus. It will be a day of overwhelming sorrow for rebellious and wicked men; for Christ's second coming shall not be realized by some universal blossoming of social peace and good will among people, nor by the emergence of some more noble and just society, but it will be a day of terror and remorse.

Then shall all the tribes of the earth mourn, and they shall see the Son of man coming on the clouds of heaven with power and great glory (Matthew 24:30).

That the quotation here from Isaiah has reference to the final judgment is implicit in the fact that only then could such a thing be. Certainly, NOW, there is no such thing as the universal acknowledgment of God, nor has there ever been; and, therefore, the great assize was the scene envisioned here.