This will happen when, on the day of the awaited resurrection, He comes a second time with glory upon the clouds."
"The Apostle Peter had already referred the words of Psalm 15 to Jesus Christ (see Acts 2:25-28), proving by them the reality of Jesus Christ's Resurrection.
But for the Apostle Paul the truth of the Resurrection is already beyond doubt. He only needs to show that the Messiah rose to eternal life.
Or, stated negatively, he must show that He was not subject to corruption, and that He bears in Himself the pledge of eternal life.
Hence salvation in Christ, the descendant of David, has an eternal and abiding power (see 2 Cor 1:10). The prophet Isaiah also says, 'I will make with you an everlasting covenant.'
Yet the same prophecy (Is 55:3-5), taken as a whole, points to another feature of the future messianic Kingdom of salvation.
According to the prophet, the future Kingdom of the Messiah will lose its limited, national character. It will be a worldwide and universal Kingdom.
There, with respect to salvation, there is neither Greek nor Jew (Col 3:11), but all are one in Christ Jesus.
David served only his own generation, his contemporaries. But the salvation manifested in his divine Descendant is not only eternal, but also universal.
It will have its purpose for all generations and peoples. Hence it is natural and in accord with the apostle's thought that, in his concluding words, he proclaims justification before God for everyone on the condition of faith in Christ."