Audio commentary on this verse

Note 7 at Rom. 10:6: Paul is saying that failure to understand justification by grace produces an attitude that, in effect, denies Christ's substitutionary work for us. A person who still believes that his performance is essential for salvation is denying that Christ is in heaven making intercession for us (Rom. 8:34). That dethrones Christ from His present position. It is like denying that Christ has ascended into heaven for us.

Likewise, a belief that we have to bear the punishment for our sins is like denying that Christ's death was sufficient by itself. If we are to be punished for our sins, then Christ might as well not have died for us.

All of this is continuing the contrast that Paul began in verse 5 between the doing of the Old Testament law and the believing of the New Testament grace (see note 5 at Rom. 10:5, p. 813). The law mentality puts us under an unbearable load of performance to obtain righteousness; faith just receives the righteousness that has already been provided through Christ.