Perhaps listen to Max read this chapter…
2Co 1:17 When I therefore was thus minded, did I use lightness? or the things that I purpose, do I purpose according to the flesh, that with me there should be yea yea, and nay nay?
2Co 1:18 But as God is true, our word toward you was not yea and nay.
2Co 1:19 For the Son of God, Jesus Christ, who was preached among you by us, even by me and Silvanus and Timotheus, was not yea and nay, but in him was yea.
2Co 1:20 For all the promises of God in him are yea, and in him Amen, unto the glory of God by us.
Gill writes better than anything I could say…
2 Corinthians 1:20
For all the promises of God in him are yea,…. This is a reason or argument proving what is before said, that “in” Christ “was yea”, since “all the promises of God in him are yea”; and shows, that God has made many promises to his people: mention is here made of “promises”, and of “all” the promises; or, as the words may be rendered, “as many promises of God”. There are some which concern the temporal good of the saints; as that they shall not want any good thing; and though they shall be attended with afflictions, these shall work for their good, and they shall be supported under them. Others concern their spiritual good; some of which relate to God himself, that he will be their God, which includes his everlasting love, his gracious presence, and divine protection. Others relate to Christ as their surety and Saviour, by whom they are, and shall be justified and pardoned, in whom they are adopted, and by whom they shall be saved with an everlasting salvation: and others relate to the Spirit of God, as a spirit of illumination, faith, comfort, strength, and assistance, and to supplies of grace by him from Christ: and others concern everlasting life and happiness, and are all of them very ancient, which God, that cannot lie, promised before the world began; are exceeding great and precious, suited to the various cases of God’s people; are free and unconditional, immutable and irrevocable, and will all of them have their certain accomplishment. These promises are all “in” Christ; with and in whom could they be but in him, since he only existed when they were made, which was from everlasting? with and in whom should they be of right, but in him with whom the covenant, which contains these promises, were made, and who undertook the accomplishment of them? where could they be safe and secure but in him, in whose hands are the persons, grace, and glory of his people? not in Adam, nor in angels, nor in themselves, only in him. Moreover, these promises are “in him yea”,
and in him amen; they are like the Gospel which exhibits them, consistent, and all of a piece; like the covenant which contains them, and is ordered in all things, and sure; and like the author of them, whose faithfulness and lovingkindness to his in Christ shall never fail; and like Christ himself, in whom they are, who is “the amen, the true and faithful witness, the same today, yesterday, and for ever”; by whose blood, the covenant, and all the promises of it, are ratified and confirmed, and in whom, who is the truth of them, they are all fulfilled. And these are
unto the glory of God by us; these serve to illustrate and advance the glory of God, when they are preached by us, and held forth by us in the Gospel, just as they are in Christ, free, absolute, and unconditional; and when they are received “by us” as believers in Christ; for the stronger we are in the faith of the promises, the more glory we give to God; faith by laying hold on, and embracing the promises, glorifies the veracity, faithfulness, power, and grace of God. The Syriac version puts the “Amen” into this last clause, and reads it thus, “therefore by him we give Amen to the glory of God”.