Paul can speak of believers as “the righteousness of God in him” because of Christ:
“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
Abraham is the classic example:
“Abraham believed God, and it was counted unto him for righteousness.”
Romans 4:3
Paul likewise says:
“Therefore being justified by faith, we have peace with God through our Lord Jesus Christ.”
Romans 5:1
So a Christian can legitimately say, “I am righteous before God,” provided the meaning is “I have been justified and counted righteous by God through faith in Christ.”
But Scripture also forbids boasting as though that righteousness originated in ourselves:
“For by grace are ye saved through faith… not of works, lest any man should boast.”
Ephesians 2:8–9
And Paul is very careful about his own righteousness:
“And be found in him, not having mine own righteousness, which is of the law, but that which is through the faith of Christ.”
Philippians 3:9
There is also an interesting distinction between positional righteousness and practical righteousness. Scripture repeatedly calls believers to live righteously (Titus 2:11–12; 1 John 3:7), while their standing before God rests upon what God has done for them in Christ.
So I would put it this way @Oakback
“I am righteous” - yes, if you mean God has justified me and counts me righteous in Christ.
“I am righteous because I am inherently good and have earned God’s acceptance” - no.
And there is a wonderful biblical basis for actually knowing this rather than merely hoping for it. Romans 5:1 says, “Therefore being justified by faith, we have peace with God through our Lord Jesus Christ.”
The believer’s righteousness is not a boast in himself. It is a declaration of what God has done in Christ.
J.