What does Romans 14:11 mean?

In the previous verse, Paul asked pointedly why any one of us would think it was our job to judge other Christians when a real judgment is coming. He called it the judgment seat of God. This is not a judgment of the salvation of believers, but an assessment of their works, as described in 2 Corinthians 5:10. Paul's specific context for this is disagreements over issues where Scripture is not clear—where the Bible does not explicitly say "don't do that." The proper response between believers with a difference of opinion on such matters should be tolerance, not judgment.

Now Paul quotes mostly from the second half of Isaiah 45:23 to support the idea of God judging our works during the end times. Isaiah looks forward to a moment when every knee will bow in acknowledgment that Christ is the Lord. Every tongue will confess—meaning to praise or swear allegiance to—the Lord. In other words, everyone gathered at that judgment will willingly recognize and submit to Christ as the Lord of all.