In Zechariah 4, three different things are mentioned: might, power, and the Spirit. The Lord says, “Not by might, nor by power.” Instead things will be accomplished by the Spirit. This verse is not talking about the might and power of God, but rather, the verse references might and power of people.
In this verse, the Lord is telling the people that things are not going to happen by physical force. Things are also not going to happen by the power of the people. Instead, the Spirit will move. This is how things will be brought to completion. The Spirit of God, as He moves, moves with both might and power. This is very different than anything from man.
Remember friends, that we do not accomplish anything by our own might and power. The Spirit of God reminds, strengthens, teaches, and encourages. In our weakness, He is our strength. As we humbly recognize our need for God, as we allow Him to freely move within us, great things happen. Jesus promised that we would do greater things (John 14:12). How? Jesus Christ ascended so that the Spirit of God could be poured out upon us. But it doesn’t end there. We cannot simply receive the Spirit; we need to continue to accept the Spirit—to allow Him to move and direct. Live by His Spirit.
“Then he said to me, “This is the word of the LORD to Zerubbabel: Not by might, nor by power, but by my Spirit, says the LORD of hosts.” – Zechariah 4:6 [ESV]