‘Now to him who is able (tow dunamenow - to him that is of power) to establish you according to my gospel and the preaching of Jesus Christ, according to the revelation of the mystery which has been kept in silence through times eternal, but now is manifested, and by the scriptures of the prophets, according to the commandment of the eternal God, is made known to all the nations unto obedience of faith,'
The letter concludes with this final doxology which ties in closely with the opening chapter of Romans. For ‘to Him that is of power' compare ‘the power of God unto salvation' (Romans 1:16); for ‘by the Scriptures of the Prophets' compare ‘which he had promised previously in the Holy Scriptures' (Romans 1:2). For ‘made known to all the nations unto obedience of faith' compare ‘for obedience to the faith among all the nations' (Romans 1:5). There appears to be a deliberate connection with the opening themes.
And the point that Paul is emphasising is that God is able to establish us ‘in accordance with my Gospel' (compare Romans 2:16) and ‘the teaching of Jesus Christ'. The thought of being ‘established' was found in Romans 1:11 where it was to be through Paul imparting to them some spiritual gift. Here that spiritual gift is seen to be in the form of ‘my Gospel'. By ‘my Gospel' he of course means the Gospel that he holds to and has presented, which he elsewhere describes as ‘the Gospel of God' (Romans 1:1), ‘the Gospel of His Son' (Romans 1:9), ‘the Gospel' (Romans 1:16). He is not claiming that it is unique to himself. And he immediately equates it with ‘the teaching of Jesus Christ', for it was to Him that he looked as the source for what he taught. ‘The teaching of Jesus Christ' could signify that his Gospel is in accordance with what Jesus Christ taught, and he makes clear in his letters that that was so. But more probably here the ‘teaching of Jesus Christ' signifies ‘the teaching concerning Jesus Christ', which is, however, clearly based on His teaching.
He then explains the even earlier source of the Gospel. It is, ‘according to the revelation of the mystery which has been kept in silence through times eternal, but now is manifested, and by the scriptures of the prophets, according to the commandment of the eternal God, is made known to all the nations unto obedience of faith.'
The Gospel is revealing ‘the mystery which has been kept in silence through times eternal, but is now manifested'. A ‘mystery is something hidden which is now revealed'. The fact that it has been ‘kept in silence through times eternal' does not mean that there had been no indication of it previously, only that it had not been openly spoken of and clearly made known. It had rather been presented in veiled form until the time came for it to be fully manifested. The Old Testament Scriptures gave many indications of it, but these indications were expressed in veiled terms the meaning of which only became apparent when their fulfilment was revealed. But now in the Gospel those indications have been turned into clear revelation. The truth that they expressed has now been clearly revealed.
That is why the ‘Scriptures of the Prophets' can now be called on as witnesses to and explanations of that ‘mystery' (Romans 1:2; Romans 3:21), in order through them to make known to all nations the truth now revealed, so that they might respond in the obedience which springs from faith. It will be noted in this regard that Paul constantly calls on the Scriptures to back his arguments (e.g. in Romans 3:10-18; Romans 4:1-25; Romans 9:25-29; Romans 9:33; Romans 10:14-21; Romans 11:26-27). And this time of manifestation was not of man's devising but was the consequence of the command of the eternal God, Who had existed throughout the times eternal when the Gospel had remained hidden. It was the eternal God Himself Who chose the time of revelation (compare Galatians 4:1).
‘To make known to all nations.' This is what Paul has constantly argued throughout Romans, that the Good News of Christ is for all nations (e.g. Romans 1:14; Romans 1:16; Romans 4:16-18; Romans 9:25-26; Romans 10:18; Romans 10:20).
Thus the Gospel is the mystery now revealed, it is based on the Scriptures of the Prophets, and its present manifestation is the consequence of God's command Who had now determined that that truth should be made known to all nations.