Romans / Question
Paul uses David's words from Psalm 32 to show that blessedness comes when God forgives sin and does not count it against a person. In Romans 4, David supports Paul's argument that righteousness is counted by grace rather than earned by works.
Romans 4 first points to Abraham, then adds David as another Scripture witness. Psalm 32's context of confession and forgiveness fits Paul's claim that justification depends on God's gracious accounting.
The passage shows that justification is not an abstract theory. It is good news for guilty people who need forgiveness and a right standing given by God.
A careful reading should not treat David as a separate route from Abraham. Paul brings both together to show one pattern of grace received by faith.