Showing how Romans 10:4 is communicating that superior righteousness from G-d is received by believing in Christ (Messiah), and that this ultimately means everlasting life without end.
A believer upholds/observes the law of Moses with this faith which allows for said righteousness that is accounted to them from above.
Previously, men would typically rely on their own hand and deeds to be accounted [relatively] righteous e.g. from the time of receiving the Torah from Moses onward – however, this was procedural, deeds based righteousness – not righteousness received by faith.
Further, after Moses, Isaiah prophesied and penned the statute which means everlasting life (Isaiah 28:16).
It is in the New Covenant that a believer will be accounted completely righteous by believing in Messiah (Christ);
I will make… righteousness the plumb line…’
(Isaiah 28:16-17 NIV)