The change in the order of the names is significant, and the change in the names not less so. Why was it that at this period the Apostle took up this new designation? I think that the coincidence between his name and that of the governor of Cyprus, who believed at his preaching, Sergius Paulus, is too remarkable to be accidental. And though, no doubt, it was the custom for the Jews of that day, especially for those of them who lived in Gentile lands, to have, for convenience' sake, two names, one Jewish and one Gentile--one for use amongst their brethren, and one for use amongst the heathen--still we have no distinct intimation that the Apostle bore a Gentile name before this moment. And the fact that the name which he bears now is the same as that of his first convert, seems to me to point the explanation. I take it, then, that the assumption of the name of Paul instead of the name of Saul occurred at this point, stood in some relation to his missionary work, and was intended in some sense as a memorial of his first victory in the preaching of the Gospel. I think that there are lessons to be derived from the substitution of one of these names for the other which may well occupy us for a few moments. I. First of all, then, the new name expresses a new nature. Jesus Christ gave the Apostle whom He called to Himself in the early days, a new name, in order to prophesy the change which, by the discipline of sorrow and the communication of the grace of God, should pass over Simon Barjona, making him into a Peter, a 'Man of Rock.' With characteristic independence, Saul chooses for himself a new name, which shall express the change that he feels has passed over his inmost being. True, he does not assume it at his conversion, but that is no reason why we should not believe that he assumes it because he is beginning to understand what it is that has happened to him at his conversion. The fact that he changes his name as soon as he throws himself into public and active life, is but gathering into one picturesque symbol his great principle; 'If any man be in Christ Jesus, he is a new creature. Old things are passed away and all things are become new.' So, dear brethren, we may, from this incident before us, gather this one great lesson, that the central heart of Christianity is the possession of a new life, communicated to us through faith in that Son of God, Who is the Lord of the Spirit. Wheresoever there is a true faith, there is a new nature. Opinions may play upon the surface of a man's soul, like moonbeams on the silver sea, without raising its temperature one degree or sending a single beam into its dark caverns. And that is the sort of Christianity that satisfies a great many of you--a Christianity of opinion, a Christianity of surface creed, a Christianity which at the best slightly modifies some of our outward actions, but leaves the whole inner man unchanged.