Which verse does Les consider one of the most important in all of Paul's epistles?

Les teaches that verse 13 is one of the most important verses in all of Paul's epistles. He urges the reader to highlight it and lock it into memory. Paul had been dealing with the nation of Israel for three chapters, but here he addresses the Gentile believers at Rome and in our own time. Paul says he is the apostle of the Gentiles. Les notes that some newer translations remove "the" and put "an," which he says is a complete violation of the text and changes Paul's whole position. If Paul were just another apostle, he would be a liar, because he claims in all his letters that it was to him and him alone that God revealed the great doctrines of grace. Paul says he magnifies his office and was never going to back down from being God's man for the Gentile world.