Romans 15:18-19:
For I will not dare to speak of any of those things which Christ hath not wrought by me, to make the Gentiles obedient, by word and deed,
Through mighty signs and wonders, by the power of the Spirit of God; so that from Jerusalem, and round about unto Illyricum, I have fully preached the gospel of Christ.
Notes on Romans 15:18-19:
Paul here shows that Christ Himself did the miracles through Paul. Paul was simply the vessel through whom Christ worked. Jesus Christ is not just sitting up in heaven seeing how well we can make it on our own in our faith walk. He is actively involved with our lives and He is actively involved in the spreading of the gospel. You don’t have to feel like a “great man of God” to be used in signs and wonders because it is Christ who does the miracles through you. It is a matter of being open and available to be used in this way.
This passage indicates that if you do NOT demonstrate the gospel with signs and wonders, you are not really preaching the full gospel.
See also:
Jesus the Healer Has Never Changed!
Healing and Evangelism
Objection: Paul Told Timothy to Drink Wine Instead of Believing God for Healing