1 Corinthians 2:4

and my language and the message I preached were not adorned with pleasing words of worldly wisdom, but they were attended with proof and power given by the Spirit,

Romans 15:19

by the power of signs and wonders, by the power of the Holy Spirit. So I have completed the telling of the good news of Christ all the way from Jerusalem around to Illyricum.

1 Corinthians 4:20

for the kingdom of God does not consist in talking but in doing.

1 Corinthians 1:17

For Christ did not send me to baptize, but to preach the good news -- but not by means of wisdom and rhetoric, so that the cross of Christ may not be emptied of its power.

1 Corinthians 2:1

Now when I came to you, brothers, I did not come and tell you God's uncovered secret in rhetorical language or human philosophy,

1 Corinthians 2:13

These truths we are setting forth, not in words that man's wisdom teaches but in words that the Spirit teaches, in this way fitting spiritual words to spiritual truths.

1 Thessalonians 1:5

for our preaching of the good news came to you not entirely in words but with power and with the Holy Spirit and with absolute certainty (for you know the kind of men we were among you for your own sakes).

2 Peter 1:16

For it was not mere stories of fancy that we followed when we told you of the power and coming of our Lord Jesus Christ, but we had been eyewitnesses of His majesty.

John 16:8-15

"And when He comes, He will bring conviction to worldly people about sin and uprightness and judgment;

Acts 20:27

for I never shrank from telling you God's whole plan.

Acts 26:28

Then Agrippa answered Paul, "In brief you are trying to persuade me and make a Christian of me!"

Romans 16:18

For such men are really not serving our Lord Christ but their own base appetites, and by their fair and flattering talk they are deceiving the hearts of unsuspecting people.

Galatians 1:10

Am I now trying to win men's favor, or God's? Or, am I trying to be pleasing to men? If I were still trying to be pleasing to men, I would not be a slave of Christ at all.

Colossians 2:4

I am saying this to keep anyone from misleading you by persuasive arguments.

1 Peter 1:12

It was made known to them that they were serving not themselves but you, in their searching for these things that have already been told to you by those who through the Holy Spirit sent from heaven brought you the good news. The angels long to take a peep into these things.

2 Peter 2:18

For by uttering arrogant nonsense, through base desires of the lower nature, they entice into immorality men who are just escaping from those who live in error,

Treasury of Scripture Knowledge

Summary

And my speech and my preaching was not with enticing words of man's wisdom, but in demonstration of the Spirit and of power:

My speech

General references

Bible References

My speech

Acts 20:27
for I never shrank from telling you God's whole plan.

General references

Luke 4:32
and they were completely astounded, because His message was spoken with authority.
1 Corinthians 4:20
for the kingdom of God does not consist in talking but in doing.