Romans 9:22-23: What If God, Desiring To Show His Wrath And To Make Known His Power, Has Endured With Much Patience Vessels Of Wrath
 What if God, desiring to show his wrath and to make known his power, has endured with much patience vessels of wrath prepared for destruction,  in order to make known the riches of his glory for vessels of mercy, which he has prepared beforehand for glory— (ESV)
Let's go back to the illustration of a potter and his clay. My experience with pottery was very short lived. I did make a few items that survived the kiln's heat. I had a few that did not survive the heat. Regardless of the outcome it was my right to make whatever I wanted with the clay and to determine how it would come out.
This is the case in a much grander scale with God. Consider that God has perfect character. I do not. God's purpose with the clay is as a master potter. He is perfect in all that he does. Paul brings up the rhetorical question concerning God's patience with vessels that he knows are not going to survive the fiery kiln.
Why does God create vessels of wrath? Scripture is saying here that God would be justified in making vessels of wrath, whom he shows patience with temporally, in order to make known the riches of his glory for those vessels of mercy. The key thing for us to see here in this scenario is that God's purpose is right and all things are for his glory.
We are not able to fully understand God's purposes. One thing we can do is to respond to his offer of mercy. If the Savior calls you to faith and repentance the proper response is not to dwell on "Why would he do that?" The proper response is to place your faith in the finished work of the cross and repent of your sins.
What is your response to the Savior? Are you wasting time questioning his purposes? Or have you submitted to his perfect purpose? Have you placed your faith in the Savior and repented of your sin? If not, do it today. Right now.