Exodus 4:10

10But Moses said to the Lord, “Oh, my Lord, I am not eloquent, either in the past or since you have spoken to your servant, but aI am slow of speech and of tongue.”

Jeremiah 1:6

6Then I said, “Ah, Lord God! Behold, bI do not know how to speak, cfor I am only a youth.”

1 Corinthians 1:17

17For Christ did not send me to baptize but to preach the gospel, and dnot with words of eloquent wisdom, lest the cross of Christ be emptied of its power.

1 Corinthians 1:21

21For since, in the wisdom of God, the world did not know God through wisdom, it pleased God through the folly of what we preach
Or  the folly of preaching
to save those who believe.

1 Corinthians 2:1-4

Proclaiming Christ Crucified

1And I, when I came to you, brothers,
Or  brothers and sisters
gdid not come proclaiming to you hthe testimony
Some manuscripts mystery (or secret)
of God with lofty speech or wisdom.
2For I decided to know nothing among you except jJesus Christ and him crucified. 3And kI was with you lin weakness and in fear and much trembling, 4and my speech and my message were not in plausible words of wisdom, but in demonstration of mthe Spirit and of power,

2 Corinthians 11:6

6 nEven if I am unskilled in speaking, oI am not so in knowledge; indeed, in every way pwe have made this plain to you in all things.

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