Isaac Newton's third law of motion states that every action brings an equal and opposite reaction. That's a spiritual law as well. If you serve the King of Kings, the prince of demons is going to react. If you serve heaven, hell will not give you a standing ovation.
This was true of the Jews who returned from Babylonian captivity to rebuild the temple in Jerusalem. Their neighbors weren't too excited about what was going on, so they "tried to discourage the people of Judah. They troubled them in building, and hired counselors against them to frustrate their purpose" (Ezra 4:4-5). They even sent a letter to the king of Persia to get this thing stopped—and it worked (see vv. 7-24).
The rebuilding of the house of God was brought to a standstill—for sixteen long years. All the flak the Jews got caused them to turn inward and focus on themselves and their own private lives, essentially saying, "The time has not come, the time that the Lord's house should be built" (Haggai 1:2).
So what did God do? He spoke to them through two prophets: Haggai and Zechariah (see Ezra 5:1). Through Haggai, for example, He said, "Is it time for you yourselves to dwell in your paneled houses, and this temple to lie in ruins?" (Haggai 1:4). In response, the people got up and got back to work (see Ezra 5:2), and the temple was eventually completed (see Ezra 6:14).
I love that what inspired them to finish the task was God's word spoken through these two prophets. There's a principle in that: the word of God does the work of God in the hearts of the people of God. So if you're facing adversity, get in your Bible. Talk to somebody who can help you frame your situation according to God's truth. It will give you courage to move forward instead of going backward or staying still.
Here's my question for you today: What work is God calling you to? Is there something that you started, but you got discouraged and stopped building—you decided, "I'm not going to finish this"? Maybe you put it aside because of thoughts from the enemy like God doesn't really want to use me. I'm not gifted. I'm not qualified.
I pray that the Lord would rebuild and rekindle the hope that perhaps has died in you, the calling that maybe you've stopped building on. May He put certain desires in your heart and fuel those desires, so that it's not by your might or power but by His Spirit moving in and through you that He accomplishes His will in the world.