what purpose does the bible have for teaching us about gods sovereignty?

We first have to understand that God's sovereignty is his right to rule over us because he created us. In fact the entire theme of the bible is the vindication of his name through his kingdom. The bible tells us about our creation, mans loss of perfection through a lie. Which led to disobedience and the reason why we get sick, grow old and die. The bible goes on o tell us God's plan to restore mankind to perfection and bringing all wickedness to an end. And not to forget restoring the earth to paradisaic conditions

To control the minds of the (mostly ignorant) masses, by instilling fear, guilt and shame. This trinity has been enormously effective for many kinds of faith systems for thousands of years. Fortunately the current age of information and communication is awakening more and more minds to the problems with this type of disinformation. 

Well, if He exists and is the only one, we probably need all the information about Him that He chose to give us.

what purpose does the bible have for teaching us about gods sovereignty?

1. Jesus taught about the sovereignty of God and how to demonstrate acceptance of that sovereignty.

2. According to Jesus this sovereignty belongs solely and exclusively to the Father whom he declares in John 17:3 to be "the ONLY true God" He goes on to declare that he was sent by this ONLY true God, meaning that he was a servant of this ONLY true God.

3. In Luke 12:47 Jesus warned that the "servant who knew his master’s will but did not get ready or act according to his will, will receive a severe beating" and in John 4:34 Jesus confirms that he did not come to do his own will but to do the will of the ONLY true God as a dutiful servant of the ONLY true God.

4. In Mark 3:35 Jesus said, “For whoever shall do the
will of GOD, the same is my brother, and sister and mother."

5. Jesus observed the law and warned in Matthew 5:19
that, “Whosoever therefore shall break one of these least commandments, and
shall teach men so, he shall be called the least in the kingdom of heaven”