In chapter 3, Nehemiah organizes the people into families and assigns them specific sections of the walls and gates to rebuild. Today we read of the opposition. The surrounding nations do not want Jerusalem to be fortified. They begin by mocking the work and saying the wall is weak and will never be finished. Then the opposition comes in the form of threats. As a result, the people need to arm themselves while they work.
Again Nehemiah is an example we can follow. He continues the work and challenges the people to depend on God, but also prepares to fight. All three had to be done. Had the work stopped, the wall would not have been finished. Had they stopped depending on God, they would have been fearful. Had they not prepared for combat, they would probably have been attacked. Like Nehemiah, we need to continue to move forward, depend on God and be prepared to face opposition.