There are 2 key bible passages that help us with this important doctrine.
1) Romans 1:16-17
1) What is justification?
It means “to declare righteous”
BF&M. Justification is God’s gracious and full acquittal upon principles of His righteousness of all sinners who repent and believe in Christ. Justification brings the believer unto a relationship of peace and favor with God. (IV.B)
2) Why are we unable to justify ourselves?
a. Good works can’t cancel your sin, but sin will ruin your good works.
b. Good works can’t save you because God doesn’t grade on a curve. - James 2:10
C. Good works can’t save you because it will never be enough.
D. Good works can’t save you because you can never be sure enough.
E. Good works can’t save you because if they could there’d be no need for Jesus.
It’s either all Jesus or all you.
How, then, are we saved? If not by our own good works, how will we get to heaven?
If not by our righteousness, then where will we find the righteousness we need?
The word used in the Reformation by both Martin Luther and John Calvin was the application of an “alien righteousness.” The word “alien” simply means “from another place or person.”
To say that we are saved by ‘alien righteousness’ means that we are saved by righteousness that comes “from another place or person.” It comes not from within us as a result of our good deeds, but from outside of us entirely.
Where can a guilty sinner find righteousness “from another place?” Only in Jesus.
Romans 8:33-34, “Who shall bring any charge against God's elect? It is God who justifies. 34 Who is to condemn? Christ Jesus is the one who died—more than that, who was raised—who is at the right hand of God, who indeed is interceding for us”
4) Justification includes four truths
Justified by God’s Grace - Romans 3:24 justified by his grace as a gift
Justified by Christ’s Blood - Romans 5:9 we have now been justified by his blood
Justified without Our Works - Romans 4:5 one who does not work but believes in him who justifies the ungodly, his faith is counted as righteousness,
Justified by Faith Alone - Romans 3:28 one is justified by faith apart from works of the law.