For they being ignorant - The ignorance of the Jews was voluntarily, and therefore criminal. The apostle does not affirm that they could not have known what the plan of God was; for he says Romans 10:18-21 that they had full opportunity of knowing. An attentive study of their own Scriptures would have led them to the true knowledge of the Messiah and his righteousness; see John 5:39; compare Isaiah 53:1-12, etc. Yet the fact that they were ignorant, though not an excuse, is introduced here, doubtless, as a mild and mitigating circumstance, that should take off the severity of what he might appear to them to be saying; 1 Timothy 1:13, “But I obtained mercy because I did it ignorantly, in unbelief;” Luke 23:34, “Then said Jesus, Father, forgive them, for they know not what they do;” Acts 7:60. Involuntary ignorance excuses from guilt; but ignorance produced by our sin or our indolence is no excuse for crime.
Of God’s righteousness - Not of the personal holiness of God, “but of God’s plan of justifying people, or of declaring them righteous by faith in his Son;” see the note at Romans 1:17. Here God’s plan stands opposed to their efforts to make themselves righteous by their own works.
And seeking to establish ... - Endeavoring to confirm or make valid their own righteousness; to render it such as to constitute a ground of justification before God; or to make good their own claims to eternal life by their merits. This stands opposed to the justification by grace, or to God’s plan. And they must ever be opposed. This was the constant effort of the Jews; and in this they supposed they had succeeded. see Paul’s experience in Philippians 3:4-6; Acts 26:5. Instances of their belief on this subject occur in all the gospels, where our Saviour combats their notions of their own righteousness. See particularly their views and evasions exposed in Matthew 23; compare Matthew 5:20, etc.; Matthew 6:2-5. It was this which mainly opposed the Lord Jesus and his apostles; and it is this confidence in their own righteousness, which still stands in the way of the progress of the gospel among people.
Have not submitted themselves - Confident in their own righteousness. they have nor yielded their hearts to a plan which requires them to come confessing that they have no merit, and to be saved by the merit of another. No obstacle to salvation by grace is so great as the self-righteousness of the sinner.
Righteousness of God - His plan or scheme of justifying people.