Nehemiah persevered in building the wall in spite of opposition by his enemies. Of course the enemies of God will oppose the works of God, but Nehemiah was also opposed by his own nobles (leading citizens) and prophets. The project was completed and the enemies, not Nehemiah, lost heart.

Nehemiah 6:12 Israel's own prophets
Then I perceived that surely God had not sent him, but he uttered his prophecy against me because Tobiah and Sanballat had hired him.

It is important to understand that opposition to the work of God can come from the people of God. Satan will hire workers from among the believers to oppose the works of God.  In the New Testament we read that Satan will use church leaders who are not saved as well as believers who are not following Christ.

1 Timothy 5:15 Here it is believing women
For some have already turned aside to follow Satan.

John 10:12 Here it is believers or unbelievers
He who is a hired hand, and not a shepherd, who is not the owner of the sheep, sees the wolf coming, and leaves the sheep and flees, and the wolf snatches them and scatters them.

2 Corinthians 11:13-14 Here it is unbelievers who are religious
For such men are false apostles, deceitful workers, disguising themselves as apostles of Christ. No wonder, for even Satan disguises himself as an angel of light.

If you are confident that you are doing the Lord's work, do not let the discouragement of Satan keep you from completing the work God has given you to do.