Zechariah / Question
"Not by might, nor by power, but by my Spirit" means Zerubbabel's work would be completed by God's enabling presence rather than human force, resources, or political strength. In Zechariah 4, the word encourages a discouraged post-exile community rebuilding the temple under God's care (Zechariah 4:6).
Zechariah sees a golden lampstand supplied by two olive trees, and the angel explains the vision with a message for Zerubbabel (Zechariah 4:1-6). Zerubbabel had laid the foundation of the house, and the promise is that his hands would also finish it (Zechariah 4:9). The "great mountain" becoming level ground pictures obstacles being overcome before the work is brought to completion (Zechariah 4:7).
The context matters because the verse is not a general slogan against planning or effort. Zerubbabel still has work to do. The point is that the decisive power behind that work is God's Spirit.
This verse is sometimes used as if it means human action does not matter. Zechariah says something more precise: human action cannot be the ultimate source of God's mission. Strength, strategy, and leadership are not enough unless God sustains the work.
The passage speaks to discouragement in small beginnings. Zechariah later asks who has despised the day of small things (Zechariah 4:10). The temple work may look fragile, but God is not limited by the scale of what people can see.
6Then he answered and spoke to me, saying, This is the word of Yahweh to Zerubbabel, saying, Not by might, nor by power, but by my Spirit, says Yahweh of Hosts.
7Who are you, great mountain? before Zerubbabel [you shall become] a plain; and he shall bring forth the top stone with shouts of Grace, grace, to it.