Does God desire the salvation of all mankind?

No.

“What if” is not a synonym for something that’s a foregone conclusion. Romans 9 contains hypothetical scenarios.

“What if” means “a question that asks someone to imagine what might happen or what might have happened.”

source: The Britannica Dictionary

His blood was paid so everyone can be saved.. provision for all of mankind.. but not everyone will be saved because they choose to reject the gift.
........ Men and brethren, what shall we do? ACTS 2:38 Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost.

Act 3:19 KJV Repent ye therefore, and be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord;

A deception of the devil is to make people believe they must be good enough, or must be saved enough before they can come to Jesus and receieve the Holy Spirit.

Jesus loves us to come to Him in any state. All we need to do is realize our need. Realize we are sinners needing Jesus..
Rom 5:7-10
7 For scarcely for a righteous man will one die: yet peradventure for a good man some would even dare to die. 8 But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us. 9 Much more then, being now justified by his blood, we shall be saved from wrath through him. 10 For if, when we were enemies, we were reconciled to God by the death of his Son, much more, being reconciled, we shall be saved by his life.

Yes, the what if doesnt change anything, God did it. He created some as vessels of wrath and fits them for destruction. Prov 16:4 confirms it as well 4 The Lord hath made all things for himself: yea, even the wicked for the day of evil.

The wicked for the day of wrath Job 21:30

That the wicked is reserved to the day of destruction? they shall be brought forth to the day of wrath.

Your what if argument is futile

Salvation has no requirements except what Christ Christ met and fulfilled to save His People. If you believe in requirements for salvation by the sinner, thats law, works, merit salvation.

No.

God didn’t create wicked people. God’s creation was good then people decided to be wicked on their own accord. This is the thesis of the entire Bible and the climax is these wicked people can gain access to grace, mercy, and forgiveness of their sins through their faith in the gospel of Christ.

You’re severely misinterpreting the entire Bible to come to these wild conclusions.

The passages you’re quoting are about people who stay wicked and never repent. In that case, yes they are reserved for judgement. God is clear in the Old Testament He is merciful to the repentant and can give forgiveness. That’s why it’s necessary to actually study this book. All of the presuppositions you’re presenting are totally out of context and disregard God’s mercy explained in the scripture.

Salvation has no requirements except what Christ Christ met and fulfilled to save His People. If you believe in requirements for salvation by the sinner, thats law, works, merit salvation.

I see you not going to accept scripture. Prov 16:4

Yes He can hold them accountable, He is God and they belong to Him

Both jews and gentiles are lost unless God saves them

Only the devil would make such a false statement. When you stand before Christ and give account, you will learn whether accusing Christ of being a liar was acceptable. The OP has given you the words of Christ Himself. So your are without excuse.

He died for the whole world. Whoever believes in Him shall be saved.

Those elected are scattered worldwide.
Not every single person, just those elected.
50 Nor consider that it is expedient for us, that one man should die for the people, and that the whole nation perish not.

51 And this spake he not of himself: but being high priest that year, he prophesied that Jesus should die for that nation;

52 And not for that nation only, but that also he should gather together in one the children of God that were scattered abroad.

I see you not going to accept scripture. Prov 16:4

4 The Lord hath made all things for himself: yea, even the wicked for the day of evil.

Again, until a person is saved, they wont be able to believe in Jesus Christ of the scripture. Now they may believe in a false christ while lost, but not the True Christ

Jn. 3:18 refutes this. As well as Jn.3:16, 36, 5:24, it goes on and on Belief is central for salvation. And that is not of ourselves but is the gift of faith that we exercise unto salvation. He gives it to every man Rom. 12:3

He can, but He would not be a just God, and we know that God is just to a fault.

Where do you get the precedent that this is a disputable matter?

Lost as in incapable of being saved. Some believe the Jews are forever lost.

No you don’t see that. What you should be seeing is I’m rejecting your contradictions. Happy New Year.