1:20 For every one of God’s promises are “Yes” in him; therefore also through him the “Amen” is spoken, to the glory we give to God.
2 Corinthians 11:6
11:6 And even if I am unskilled 1 in speaking, yet I am certainly not so in knowledge. Indeed, we have made this plain to you in everything in every way.
1 snUnskilled in speaking means not professionally trained as a rhetorician.