In preaching the gospel to others, we don’t always say the right thing in a given situation, we don’t always know what to say, or afterwards we think, “Oh, I should have said that!” We are weak in ability, and at times fail in the task.
“But we have this treasure in earthen vessels, so that the surpassing greatness of the power will be of God and not from ourselves,” 2 Corinthians 4:7
We aren’t from ourselves mighty in deed, mighty in speech, unerring in our knowledge of what to say, perfect in our ability to preach. We are earthen vessels, imperfect. This according to the will of God, so that indeed the power is from Him, and not of ourselves.
How much then we need to preach the truth, and not our own understandings! How much we need to hold to the truth, and not speculate into things of which we have no knowledge or skill. The power is always of Him and not of us.
"Let him who has My word speak My word in truth. What does straw have in common with grain?" declares the LORD. "Is not My word like fire?" declares the LORD, "and like a hammer which shatters a rock?” Jeremiah 23:28-29
He has entrusted the gospel to us, and it is the power of salvation. We are imperfect in our spreading of the seed, but it is the seed which causes growth, not our imperfections.