2Cor 1, 19 Jesus Christ was not "yes" and "no", but "yes"

(2Cor 1, 19) Jesus Christ was not "yes" and "no", but "yes"

[19] For the Son of God, Jesus Christ, who was proclaimed to you by us, Silvanus and Timothy and me, was not "yes" and "no," but "yes" has been in him.

(CCC 1063) In the book of the prophet Isaiah, we find the expression "God of truth" (literally "God of the Amen"), that is, the God who is faithful to his promises: "He who blesses himself in the land shall bless himself by the God of truth [amen]" (Isa 65:16). Our Lord often used the word "Amen," sometimes repeated (Cf. Mt 6:2, 5, 16; Jn 5:19), to emphasize the trustworthiness of his teaching, his authority founded on God's truth. (CCC 215) "The sum of your word is truth; and every one of your righteous ordinances endures forever" (Ps 119:160) "and now, O LORD God, you are God, and your words are true" (2 Sam 7:28); this is why God's promises always come true (Cf. Dt 7:9). God is Truth itself, whose words cannot deceive. This is why one can abandon oneself in full trust to the truth and faithfulness of his word in all things. The beginning of sin and of man's fall was due to a lie of the tempter who induced doubt of God's word, kindness and faithfulness. (CCC 422) “But when the time had fully come, God sent forth his Son, born of a woman, born under the law, to redeem those who were under the law, so that we might receive adoption as sons” (Gal 4:4-5). This is “the gospel of Jesus Christ, the Son of God” (Mk 1:1): God has visited his people. He has fulfilled the promise he made to Abraham and his descendants. He acted far beyond all expectation - he has sent his own “beloved Son” (Mk 1:11; cf. Lk 1:5, 68).