"***** Some ministers make the mistake of supposing that success depends on drawing a large congregation by outward display, and then delivering the message of truth in a theatrical style. But this is using common fire instead of the sacred fire of God's kindling. The Lord is not glorified by this manner of working. Not by startling notices and expensive display is His work to be carried to completion, but by following Christlike methods. “Not by might, nor by power, but by My Spirit, saith the Lord of hosts.” [ Zechariah 4:6 .] It is the naked truth which, like a sharp, two-edged sword, cuts both ways, arousing to spiritual life those who are dead in trespasses and sins. Men will recognize the gospel when it is brought to them in a way that is in harmony with God's purposes. GW 383.2"
"Then he answered and spake unto me, saying, This is the word of the Lord unto Zerubbabel, saying, Not by might, nor by power, but by my spirit, saith the Lord of hosts."
Ellen White directly references Zechariah 4:6 in this passage.