Our standing with God rests firmly in Christ and His righteousness. He who knew no sin became sin in order to remove our sin nature.
For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him. 2 Corinthians 5:21 KJV
Jesus took our unrightousness upon Himself and gave us (imputed to us) His righteousness. The sinless Lamb of God shed His blood and cleansed us from all unrighteousness. We are no longer slaves to sin and in bondage to the fear of death.
He ever lives as our High Priest and interceeds for us. He offered His blood on the heavenly altar once and for all. We now, in Christ, and by virtue of His blood, have bold access to the throne of grace.
For we have not an high priest which cannot be touched with the feeling of our infirmities; but was in all points tempted like as we are, yet without sin. Let us therefore come boldly unto the throne of grace, that we may obtain mercy, and find grace to help in time of need. Hebrews 4:15-16 KJV