‘For I bear them witness that they have a zeal for God, but not in accordance with knowledge, for being ignorant of God's righteousness, and seeking to establish their own, they did not submit themselves to the righteousness of God.'
The tragedy of the Jews was that while they had a kind of zeal for God, (no people were more religious than they), their zeal was ‘not in accordance with knowledge (epignosis - higher knowledge)' (compare Romans 10:19). In other words their zeal was operating outside revealed truth. They had failed to interpret the Scriptures correctly. They were thus ignorant of the truth. For those Scriptures had pointed to a humble Messiah (Zechariah 9:9; Isaiah 52:13 to Isaiah 53:12), and they had stressed the need for ‘circumcision of the heart' (Leviticus 26:41; Deuteronomy 10:16; Deuteronomy 30:6; Jeremiah 4:4; Jeremiah 9:26) and for a work to take place in their hearts (Jeremiah 31:31-34; Ezekiel 36:26-27; Psalms 51:7-12). But this was something that they had failed to recognise. Thus the very truth that they believed that God had given them was instead condemning them (compare Romans 2:17-24; Romans 3:19-20), because what the Law gave them was the knowledge of sin (Romans 3:20), whilst on the other hand they had overlooked the emphasis of the Scriptures on the fact that their righteousness was to come from God (Romans 4:3; Romans 4:7-8; Genesis 15:6; Psalms 32:1-2; Psalms 51:7-12; Isaiah 46:13; etc). So in seeking to establish their own righteousness by constant obedience to the Law of Moses (in accordance with the traditions of the elders), they were merely compounding their sins. This was because the Law continually condemned them, whilst they themselves were missing out on much of what the Scriptures taught.
And this state of affairs resulted from the fact that they were ignorant of the righteousness of God, and did not submit themselves to it. Reference to Romans 3:20 to Romans 4:25; Romans 5:15-19 establishes what this righteousness of God was. It was the free gift of righteousness, a righteousness which God had brought to His people in Jesus Christ the Messiah as a consequence of His death for them. Thus they had failed to submit to the Messiah and the message that He had brought. They had failed to submit to the truth.
‘Seeking to establish their own (righteousness).' There is an echo here of Deuteronomy 9:4-6 where Moses pointed out to Israel that it was not because of their own righteousness that God was giving them the land, but rather in fulfilment of the word of the Lord given in His promises to their fathers ((Deuteronomy 9:5), a permanent reminder that God's promises are not contingent on ‘our own righteousness' but on His elective purposes. There too they were called on to respond to the word of the Lord, not depending on their own righteousness.