‘But as God is faithful, our word toward you is not yes and no. For the Son of God, Jesus Christ, who was preached among you by us, even by me and Silvanus and Timothy, was not yes and no, but in him is yes. For however many be the promises of God, in him is the yes, wherefore also through him is the Amen, to the glory of God through us.'
He denies utterly the suggestion that he is negative or fickle by pointing to the faithfulness of the God, with Whose word he comes and Whom he seeks to be like, and Who came in Jesus with a positive message, not one that was ‘yes' and ‘no', but that was ‘yes, yes' and ‘Amen'. This then brings out the positiveness of Jesus, Whom Paul preached among them. He too was not ‘yes' and ‘no'.
This is said not just in order to vindicate himself, but to vindicate the very message that he preaches. As certainly as God is faithful, so is his word faithful to them and not ‘yes' and ‘no', for he serves the faithful God (Deuteronomy 7:9; Isaiah 49:7) and brings His word. And just as certainly did God's Son Jesus also have this faithfulness and this certainty, in that in Him also was ‘yes'. And he was preached by Paul, Silas and Timothy, so that they too were involved in His ‘yes', and He was preached among them so that they might have experience of the power of Christ at work through Paul.
For however many were the promises of God, God's Son Jesus Christ said ‘yes' to them all. The whole of the Old Testament carried His backing. He was totally faithful to the promises of God, and confirmed that they would be fulfilled (see Matthew 5:18). So there is no failure in the faithfulness of God, or in His promises, or in Jesus Christ His Son. Nor would there be in those who proclaimed Him in power.
‘Wherefore also through him is the Amen, to the glory of God through us.' So through God's Son Jesus Christ everything that Paul proclaims (‘through us'), based as it is on His word, receives His ‘Amen'. It has His guarantee. It is sure and certain, thus bringing glory to God. And that is why the church can say ‘Amen' to it all. Indeed in Revelation John can say that Jesus is ‘the Amen' as the faithful and true witness (Revelation 3:14). And that faithful and true witness is confirmed in His servants who proclaim His truth, who themselves proclaim the faithfulness of God, by the power revealed through them, such power that the testimony of Christ was confirmed in those who heard (1 Corinthians 1:6; 1 Corinthians 2:4). For he and his fellow-workers are so closely connected with God and with Christ that they cannot be but faithful. They are imitators of God and of Christ, from whom they receive their power in their ministry.
‘Our word towards you is not yes and no.' For their word is the word of the faithful God, it is the word of God's Son Jesus Christ, to Whom all was ‘yes', with Whom there is no ‘no'. And this word will be reflected in all the words they speak, whether in preaching or in promises. Thus there can be no fickleness in them.
For however many promises of God there are, God's Son Jesus Christ says ‘yes' to them all. And in the same way when He is acting through them it is with the ‘Amen', to the glory of God. For they come in Christ's name under Christ's lordship, and through Him there can only be ‘Amen' (let it be so) in the things of God.
‘Who was preached among you by us, even by me and Silvanus and Timothy.' He, Silas (Silvanus) and Timothy had all preached among them ‘the Son of God, Jesus Christ'. The use of ‘Son of God' here is the more directly to connect Jesus Christ to the God Who is faithful. Could those who preached such a One with such power themselves be fickle?