But now the righteousness of God apart from the law is revealed, being witnessed by the Law and the Prophets, 22 even the righteousness of God, through faith in Jesus Christ, to all and on all who believe. For there is no difference; 23 for all have sinned and fall short of the glory of God, 24 being justified freely by His grace through the redemption that is in Christ Jesus, 25 whom God set forth as a propitiation by His blood, through faith, to demonstrate His righteousness, because in His forbearance God had passed over the sins that were previously committed, 26 to demonstrate at the present time His righteousness, that He might be just and the justifier of the one who has faith in Jesus. — Romans 3:21-26.
Only Jesus Christ can justify a sinner, be he Gentile or Jew. Given that ‘all have sinned and fall short of the glory of God’, it is the righteousness of God, put to our account when we put our faith in Christ, that is seen by God as ours and justifies us because we have no righteousness of our own. Not only that, but Christ shed His blood as a ‘propitiation’. That means that, when Christ died on the cross for our sins, our wicked rebellion that offended our holy God was punished by His wrath falling on Christ in our place. Thus cleansed by His precious blood and with His righteousness put to our account, we find that, as we put our faith in Him, we are justified by Him who is both just and the Justifier. [Source: The Bible Panorama.]