As sinners it is impossible for us to meet God’s standard of righteousness– “Romans 3:23 For all have sinned, and come short of the glory” AND even the best things we do as sinners are like filthy rags in God’s sight–
“Isaiah 64: 6 But we are all as an unclean thing, and all our righteousnesses are as filthy rags ; and we all do fade as a leaf; and our iniquities, like the wind, have taken us away.”
The righteousness of God is being credited to us through Christ. In fact it is being offered to us as a free gift from God.
Romans 3:21 But now the righteousness of God without the law is manifested, being witnessed by the law and the prophets;
Our salvation is made possible by the redemption that is in Christ.
Romans 3:24-26 being justified freely by His grace through the redemption that is in Christ Jesus,
whom God set forth to be 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,
to demonstrate at the present time His righteousness, that He might be just and the justifier of the one who has faith in Jesus.