Deuteronomy 6:25→ And it will be accounted as righteousness (conformity to God’s will in word, thought, and action) for us if we are watchful to do all this commandment before the Lord our God, as He has commanded us. Amp
The perfect keeping of the law was the measure of our right standing before God. Whoever kept the law was considered righteous. It is what gave man confidence to stand before the God. All the promises of the Old Covenant were based on man’s righteousness which was in turn based on man’s performance.But none of us are righteous (on his own merit). No, not one. It is therefore futile to think that our observance of the law will make us acceptable before God.
Romans 3:10→ As it is written, None is righteous, just and truthful and upright and conscientious, no, not one. Amp
The pursuit of our own righteousness, like trying to keep the law, is as much a fruitless endeavor as it is a burdensome affair. Jesus came to lift the burden from us and to abolish the written code that stood against us. Our righteousness cannot satisfy the requirements of an infinitely Holy God because day by day it is weakened by our flesh.
Isaiah 64:6→ For we have all become like one who is unclean [ceremonially, like a leper], and all our righteousness (our best deeds of rightness and justice) is like filthy rags or a polluted garment; we all fade like a leaf, and our iniquities, like the wind, take us away [far from God’s favor, hurrying us toward destruction]. Amp
The Bible stands clear that no one will be declared righteous by his acts of righteousness or by keeping the law.
Romans 3:20→ For no person will be justified (made righteous, acquitted, and judged acceptable) in His sight by observing the works prescribed by the Law. For [the real function of] the Law is to make men recognize and be conscious of sin [ not mere perception, but an acquaintance with sin which works toward repentance, faith, and holy character].Amp
The law makes us understand and recognize what sin is but it is not in itself a remedy of sin. Our righteousness comes only from Christ. By becoming sin and by fulfilling all that was written in law, He became what He was not so that we could become what we were not. He who was not sin became sin so that we could become the righteousness of God.
2 Corinthians 5:21↓ Our righteousness is no longer earned but is imputed and is based on faith in Christ.
Romans 3:21-24→ But now the righteousness of God has been revealed independently and altogether apart from the Law, although actually it is attested by the Law and the Prophets,
22Namely, the righteousness of God which comes by believing with personal trust and confident reliance on Jesus Christ (the Messiah). [And it is meant] for all who believe. For there is no distinction,
23Since all have sinned and are falling short of the honor and glory which God bestows and receives.
24[All] are justified and made upright and in right standing with God, freely and gratuitously by His grace (His unmerited favor and mercy), through the redemption which is [provided]. Amp