Summary: A message relating how Jonah told the Ninevites they would be destroyed, and yet they weren't, and how on Rosh Hashana a persons fate is written in God's book, but it can be changed before the closing of the gates on Yom Kippur.
Jonah is read every year on the most Holy Day in the Jewish calender, the day of Atonement. (Yom Kippur) To understand why we have to back up and explain a little bit about the Jewish feasts.
There are 7 major Jewish feasts. The Hebrew word for feasts (moadim) literally means "appointed times." You need to grasp a hold of that meaning of the word, because it reveals that the feasts tell us about God's appointed times. Or said another way the feasts teach us about things that God has appointed to happen.
This is what we read in the book of Colossians:
Col 2:16 Therefore do not let anyone judge you by what you eat or drink, or with regard to a religious festival, a New Moon celebration or a Sabbath day.
Col 2:17 These are a shadow of the things that were to come; the reality, however, is found in Christ.
In other words the feasts are a shadow of things that they teach us about Christ. As I said earlier there are 7 feasts and they are divided into two seasons of the year, Spring feasts, and Fall feasts. So they deal with the begninning of, and the close of the harvest. Things appointed with the beginning of the harvest and things appointed with the closing of the harvest. Spiritually they teach of things that would happen at the beginning of the church age and the close of the church age. (The beginning and end of the harvest)
Things appointed in Spring or early harvest are the Passover, Unleavened Bread, First Fruits, and Pentecost.
Those 4 feasts or appointed times have already been fulfilled. I don't have time to explain all that today. But I will use one of them to show how they are a shadow of Christ. In the Passover, a lamb was slain, its blood put on the doorposts of the house, and when the death angel came, every house that had blood sprinkled on the doorposts was spared. In the NT we read: "Christ our Passover is sacrificed for us..." and again He that believeth on the Son has everlasting life, He that believeth not the wrath of God abidieth on Him. Jesus is the Lamb of God that taketh away the sins of the world. So when we ask God to spiritually cover us with the blood of the Lamb, then we can have assurance that when the wrath of God is poured out, the death angel will pass us by.
So there were 4 Spring feasts, that have already been fulfilled in Christ, there are also 3 Fall feasts that have yet to be fulfilled. They have to do with the end of God's harvest season.
Rev 14:15 And another angel came out of the temple, crying with a loud voice to him that sat on the cloud, Thrust in thy sickle, and reap: for the time is come for thee to reap; for the harvest of the earth is ripe.
The feasts that will be fulfilled in this appointed time are: The feast of trumpets, The day of Atonement, and the feast of tabernacles.
The feast of trumpets is the first of the fall feasts. So then it is the next thing on God's calander of appointed times. This feast is about two things: 1. It is the beginning of the Jewish civil year. 2. It is a short period of time that is given so that judgment can be averted.