1 Corinthians 2:4-6

And my message and my preaching were very plain. Rather than using clever and persuasive speeches, I relied only on the power of the Holy Spirit. I did this so you would trust not in human wisdom but in the power of God. Yet when I am among mature believers, I do speak with words of wisdom, but not the kind of wisdom that belongs to this world or to the rulers of this world, who are soon forgotten.