The prophet Elijah had a pretty tough calling from God, to speak words of warning and judgment to the evil King Ahab and his wicked wife Jezebel. Dealing with the reality of sin and evil can be exhausting. But God speaks words of hope and life to tired sinners.
I Kings 19:1-6, 9b-18 (The Lord appears to Elijah)
Matthew 11:25-30 (Rest for the weary)