Dear Harold
I have some questions for you, if I may.

Question 1...Who or whom are the vessels of wrath in Romans 9:22?

Dear ??,
Thank you for your inquiry.
The answer to the above contextually is, the Pharaoh of,  V.17, generally, it would apply to all rebellious sinners who live and die in their sins.

v. 22  What if God, willing to show his wrath, and to make his power known, endured with much longsuffering the vessels of wrath fitted to destruction

The question here is who fitted them for destruction?  Was it God, or themselves?  The wages of sin is death. Does God fit men to these wages or does the sinner do that by their sins?  The answer is evident.

These verse gives us the answer Rom. 2: 4  Or despisest thou the riches of his goodness and forbearance and longsuffering; not knowing that the goodness of God leadeth thee to repentance? 5  But after thy hardness and impenitent heart treasurest up unto thyself wrath against the day of wrath and revelation of the righteous judgment of God;
They fit themselves to this judgment.  They are going to hell, but God didn't even prepare it for them, or them for it.  Then shall he say also unto them on the left hand, Depart from me, ye cursed, into everlasting fire, prepared for the devil and his angels Matt 2541

It would be strange that God would fit these vessel to destruction in hell and yet never prepared hell for them.

Question 2.   Who or Whom are the vessels of mercy in Romans 9: 23?

Those that do this,  Proverbs 28:13  He that covereth his sins shall not prosper but whoso confesseth and forsaketh them shall have mercy.  This is the essence of repentance. And there is no mercy without it.

God two attributes in salvation is mercy and grace.  Tit 3:5 " according to His mercy He saved us...." By grace are ye saved through faith..." Eph 2: 8

God's attribute toward the sinner is righteous wrath. John 336,,, the wrath of God abideth (present tense) on him"

Repentance will change this attribute of wrath to mercy. Prov. 28:13.

Mercy come first. This is God holding back the judgment that we rightly deserve, He mercy rejoiceth over judgment James 213, ".....and mercy rejoiceth against judgment."

V.23  And that he might make known the riches of his glory on the vessels of mercy, which he had afore prepared unto glory,

Notice the difference here. "He has prepared unto glory."  This is not said of the vessels of wrath. They are not prepared and no glory to God.

God has no pleasure in the death of the wicked. Ezekiel 3311  Say unto them, As I live, saith the Lord GOD, I have no pleasure in the death of the wicked; but that the wicked turn from his way and live turn ye, turn ye from your evil ways; for why will ye die, O house of Israel?

If the view of the sovereignty is as expressed by many, why would a Sovereign God who has no pleasure in the death of the wicked get pleasure by electing them to salvation?  God does not get glory in the death of the wicked.  Where is the god of the unconditional election?  How can you reconcile God displeasure of the death of the  wicked and His sovereignty?  If He is sovereign, in your way of seeing Him,  then He would have to have pleasure in the death of the wicked.

Here is something for you to think about.  God's sovereign grace is never separated from truth.  Grace and truth came by Christ.

There are some things God cannot do.  It would violate His own person and attributes.

According to man's theology how could they turn if God had not foreordained that do so. This would violate His attribute of mercy and truth.

Question...3  Is it perhaps those He hath called, according to v. 24?

Sure thing. It is those that are called and those that are called are those that respond to the call out from darkness to light. 1 Peter 2:9 and respond to the call to repentance. Luke 5: 32 I came not to call the righteous, but sinners to repentance.

24 Even us, whom he hath called, not of the Jews only, but also of the Gentiles?

 What of the called?   Romans 8: 28-30 V.28  And we know that all things work together for good to them that love God, to them who are the called according to his purpose.

These are already the saved.

29  For whom he did foreknow, he also did predestinate to be conformed to the image of his Son, that he might be the firstborn among many brethren.

30  Moreover whom he did predestinate, them he also called

Predetermined to be conformed to the image of His Son. This is what they are to BE, not where they are called to GO. Sure they are going to be with Him, but that is not what is in view here.

That is the call of the Spirit through the preaching of the gospel and the response of the sinner. They are the called.

and whom he called, them he also justified and whom he justified, them he also glorified.

 I will agree with the scriptures. Sounds like not only a purpose,

Purpose only.

but also a destination.

Destiny, (heaven or hell) is not in view in these verses.  It is speaking of the saved who will be conformed to the image of Christ and be glorified. It does not say here or anywhere that anyone was ever elected to be PUT in Christ. I am elected of God because I am IN Christ. He is the elect of God.

Glorification will only apply to those in heaven, right?

Right, but glorification is not to a destiny, but to the image of Christ.  Actually, it will take place a bit before we get to heaven. It will take place at the Rapture, in a moment.

Warmly,

Harold