There are many lessons we can learn from the book of Jonah, the following are a few from chapters 3 & 4.

Jonah 3:
The LORD God used His reluctant prophet Jonah to warn his enemies in Nineveh of God’s coming judgment…how is the LORD using you to warn your enemies?

Jonah did proclaim God’s words in the heart of the sinful city…where is the LORD sending you to proclaim His true word?

The people and the king of Nineveh repented by fasting, wearing sackcloth and even to sitting in ashes…your words about God and His ways are important and God will use them for His purposes.

God saw the actions of the people of Nineveh and because of His compassion, He relented and did not bring calamity on that city at that time. (Later in history, He did bring defeat to Nineveh in Assyria when the Babylonians defeated them.)

Jonah 4:
Jonah knew God’s character: (NASB) Jonah 4:2 “…I knew that You are a gracious and compassionate God, slow to anger and abundant in lovingkindness, and one who relents concerning calamity.”…have you experienced any of these character traits of God?

Jonah was angry at God and sulked…how honest are you with God?

God patiently and repeatedly pointed out to Jonah that he did not have a good reason to be angry…how closely are you listening to God and responding to His patience toward you?

The story of Jonah is left dangling, there is no ‘ending’…how will others ‘read’ your story? 

God’s concern was for the people of Nineveh and in His compassion He warned them and they responded…what is God’s concern for those you have a hard time dealing with on a daily or regular basis?