1 Thessalonians 1:5

In power, and in the Holy Ghost, and in much assurance; the last clause of this verse shows that the immediate reference of these words is to the apostle and his associates. Their preaching was in power, and in the Holy Ghost, and in full assurance of what they uttered. But this cannot be separated from the effect on their hearers. To them also their preaching was attended with the power of the Holy Ghost; it was embraced with full conviction of its truths, and led them to break off their sins and turn to the Lord. See verse 1 Thessalonians 1:6.