Charles Spurgeon explained, "Understand that the only people who can be justified by God are those who do not attempt to justify themselves. Realize that you need God to make you just; He is the One who will enable you to stand before His judgement seat in the righteousness that only Christ can provide for you."
Believers are justified by God's grace through faith in Christ. Grace is the gift of God. Let us be clear, faith itself does not merit the gift but only receives it. Faith is trusting or relying upon the righteousness of Christ, and Christ alone.
Believers are justified by God at the cross of Jesus. All our sins are taken away. "The blood of Jesus Christ His Son cleanses us from all sin" (1 John 1:7). Believers receive the righteousness of God in Christ (2 Corinthians 5:21). The gospel exchanges our sins for the righteousness of Christ.
Believers are justified by God through the resurrection of our Lord Jesus Christ. God raised Jesus from the dead to justify every believer (Romans 4:24-25; 10:9). Our hope is built on nothing less than Jesus blood and righteousness. The resurrection of Jesus Christ proves the gospel, that God justifies believers at the cross.
Believers are justified by God's grace in Christ alone (Galatians 2:21). Christ is the believer's justification. Grace is defined as the unmerited favor of God. It is unmerited on our part, because it is based upon the merits of Christ alone.