Consider Paul, too: in order to prove that it is fitting for us all to stand before Christ’s tribunal, he brings another remark of the prophet to bear: “As I live, every knee shall bow before me” (Isaiah 45.23). To be sure, it is the God of Israel, whom Moses had testified was the one and only God, who speaks in the prophet. And yet Paul testifies that this praise is appropriate for Christ (Romans 14.11; Philippians 2.10). Therefore he is the same one who swears by his own life that he will not give his glory to another. And in vain will they try to evade the conclusion that God will be judge in the Person of Christ, because he has given all judgment to the Son, since Paul assumes that it is well known that what is said in the prophet about the supreme dominion of God is truly appropriate for Christ.
By similar reasoning, he proves from Isaiah again that Christ is the rock of offense for the Jews, although, nevertheless, the prophet would not proclaim this about anyone except the one and only God (Isaiah 8.14; Romans 9.33; 1 Peter 2.7). Now, Paul would wrongly apply to Christ what David affirms about the highest God, unless we confess that Christ is included under that deity. David addresses the one and only God in the following words: “You ascended on high” (Psalm 68.19). Paul teaches that this passage had been fulfilled in Christ (Ephesians 4.8).1