How do we know that Christ's obedience justifies us?

Romans 5:19 states, 'For as by one man's disobedience many were made sinners, so by the obedience of one shall many be made righteous.' This verse illustrates how Christ's obedience to God's law and His sacrificial death on the cross directly contribute to our justification. His righteousness is imputed to us, as seen in 2 Corinthians 5:21, which articulates that God made Christ, who knew no sin, to be sin for us, so that we might become the righteousness of God in Him. Our justification, therefore, is completely dependent on Christ’s work, not our own, affirming the grace of God in our salvation.