Discouragement sets in to all pastors. It is an inevitable occurance in the life of any pastor. The question is not, "Will I encounter discouragement in the ministry?" but rather "When will I encounter discouragement and how will I react to it?" It is tempting to persist in the discouragement and become more and more discouraged. But that is not how God would have the pastor to react.
It is much better to acknowledge the discouragement, repent where repentance is needed, and go to the Word of God for encouragement. As a pastor, I found that encouragement this week in Exodus 5 & 6. In this passage, Moses has been called by God to deliver the people of Israel from Egypt. Reluctantly Moses obeys what God has said and goes to Pharaoh and tells him to let the people of Israel go and worship the LORD. Pharaoh refuses and instead makes the labor of the Israelites more burdensome. The people complain to Moses about how bad things are and how he has made things worse for them. Moses cries out to God in discouragement and frustration about how things are not going the way they should and how God is not delivering the people, but things are getting worse.
God then reveals Himself again to Moses and tells him to go and once again tell the people who He is and that He will deliver them and be faithful to all His promises to their fathers. But again they did not listen to Moses. Then the LORD tells Moses to once again tell Pharaoh to let the people of Israel go. Moses replies in discouragement and frustration again that his own people will not listen to him, much less Pharaoh.
Then the Word of God says,
But the LORD spoke to Moses and Aaron and gave them a charge about the people of Israel and about Pharaoh king of Egypt: to bring the people of Israel out of the land of Egypt.
Sometimes in the midst of a pastor being obedient to God, things might get "seemingly" worse for the people. Attendance may decrease. Offerings may drop off. Fewer decisions may be made, but the pastor must not desist from the path of obedience to God. Even in the midst of a negative reaction from some of the people and the seemingly impossibility of the task given to Moses from God the conclusion of Exodus 6:13 is that God had given a charge and God's man must be obedient.
Pastors: In the midst of the temptation to be discouraged and stay discourage and to let that discouragement lead to disobeying the leadership and Word of God, remember the charge God has given you in His Word and follow His leadership. God has spoken and He has charged you with a charge and a calling. Lovingly, fulfill it.