Helaman 5

As Nephi and Lehi remembered the words of their father, Helaman -

"...it came to pass that they did preach with great power, insomuch that they did confound many of those dissenters who had gone over from the Nephites, insomuch that they came forth and did confess their sins and were baptized unto repentance, and immediately returned to the Nephites to endeavor to repair unto them the wrongs which they had done."  (Book of Mormon | Helaman 5:17)

The scriptures speak much concerning the "power of the word".  Obviously, Nephi and Lehi had the Spirit such that they did preach with great power.  In my mind, the reference to "dissenters" suggests to me, those that had apostatized or had gone inactive.

In a time when we have been challenged to increase our sacrament meeting attendance, the answer would be to preach with great power.