As we know, Paul wrought mighty miracles, as Peter and the Pentecostal believers had done. Indeed, a comparison of Paul’s miracles with those of Peter shows Paul’s to have been the mightier. This was mainly in divine confirmation of his apostleship, since Paul was not one of the twelve (II Cor. 12:11,12).
But it is clear from a study of Paul’s ministry and his epistles that these miraculous demonstrations were to vanish away as the dispensation of grace was fully ushered in (See I Cor. 13:8; Rom. 8:22,23; II Cor. 4:16-5:4; 12:10; Phil. 3:20,21; I Tim. 5:23; II Tim. 4:20). In fact, in the last seven of Paul’s epistles nothing whatever is said about signs, miracles, healings, tongues, visions or the casting out of demons.
How, then, does God now empower His servants in their conflict with Satan and his demons? The answer is: by the Holy Spirit through His Word, as it is preached with conviction. There is a great volume of evidence as to this in Paul’s epistles, including his early epistles. Two examples:
I Cor. 2:4: “And my speech and my preaching was not with enticing [persuasive] words of man’s wisdom, but in demonstration of the Spirit and of power.”
Mark well, this was power in his preaching, not in performing miracles. Indeed at the very same time when he proclaimed his God-given message with such power, he himself was very weak, for in the preceding verse he says:
“And I was with you in weakness, and in fear, and in much trembling.”
The other example is I Thes. 1:5:
“For our gospel came not unto you in word only, but also in power, and in the Holy Ghost, and in much assurance…”
In Thessalonica too, Paul had suffered much opposition and persecution, until the whole city was in an uproar (Acts 17:1-5), and this may well have been the result of his powerful preaching. Out of the “uproar,” however, sprang the beloved Thessalonian church, an example and inspiration to those won to Christ under more benign circumstances. source