The power of the Spirit
Zech 4:6: "Then he said to me, ‘This is the word of the Lord to Zerubbabel saying, not by might nor by power, but by My Spirit,' says the Lord of hosts" (NASU).
When the remnant of the Jews returned to Jerusalem from the Babylonian captivity, they tried to rebuild the temple, but became discouraged. They had neither the military strength nor the physical power needed to accomplish the task. But, God reminded them it is not human strength or power that accomplishes His will; it is the Spirit. With this encouragement, Zerubbabel and the people completed the temple.
Our culture tells us we must have money, power, beauty, or fame to be successful. But God often works through the small and the weak to accomplish His goals. He asks us to depend on His strength, not ours. When we embrace our weakness, we can receive His strength.
Strength in parenting comes from relying on God's power, not our own.