This is how Calvinism falls. I read a book from the Primitive Baptist church, I think it's also known as Particular Baptist. The book makes a case for Calvinism;s TULIP arrangement and it explains that the subsequent doctrines are predicated on the truth of the prior doctrine. That is, if T, then U. If U, then L. If L, then I, and if I then P. If you don't know what I'm talking about go read up on Calvinist soteriology because I'm not here to hold your hand and walk you through it.
Then, working backwards, if P falls, then Calvinism falls, and this is by Calvinists' own admission.
Romans 10:13 "For whosoever shall call upon the name of the Lord shall be saved."
Eternal Security T U L I P
To borrow this formula of Romans 10: If a man confesses his sin (a1) and makes (footnote 1) Christ Lord in his life (a2) by confessing with his mouth,
And he falls away from the faith (footnote 2,3),
Arminianism says he was saved and then turned back to the darkness, And Calvinism states he was never truly saved,
Then Calvinism holds the pleading of the blood (a1) and declaring Christ's Lordship in one's life (a2) insufficient, and therefore His blood.
1 1 John 1:9 "If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness."
2 2 Peter 2:20-22 "For if after they have escaped the pollutions of the world through the knowledge of the Lord and Saviour Jesus Christ, they are again entangled therein, and overcome, the latter end is worse with them than the beginning. For it had been better for them not to have known the way of righteousness, than, after they had known it, to turn from the holy commandment delivered unto them. But it is happened unto them according to the true proverb, The dog is turned to his own vomit again; and, The sow that was washed to her wallowing in the mire."
3 Hebrews 6:4-6 "For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost, and have tasted the good word of God, and the powers of the world to come, if they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame."
What it boils down to is this: If it is possible that a man could confess is sins, call upon the name of the Lord and make Christ the center of his life, and for him to still not be saved, because God from some time ago predestinated that man to not be saved, then the Christian religion is totally without merit and it would all be a horrible lie, in my opinion. We would be ruled over by some tyrannical Calvinistic God who has zero compassion or mercy on anyone but lives solely for His own personal gratifications and lust.
I definitely see where the unbelievers are coming from because I would not like that story much either. And many Christians stick by this story which is as much of a turnoff to the faith as anything else.
If perseverance falls, then irresistible grace falls as well. Irresistible grace is the idea that those who He predestined to be saved have no power to reject His free gift, and therefore, they will persevere in that faith.
But if perseverance in wrong, the irresistible grace is wrong too.
If this irresistible grace is wrong, then limited atonement is wrong. Jesus died for those who His father did predestinate and that in order to assure they are saved provides an irresistible grace and that they will persevere. But if perseverance is wrong and irresistible grace is wrong, then limited atonement is wrong.
Unconditional election must fall as well. If the election is assured through no action at all on man's part but only bought at the price of Jesus' shed blood, then there must be an atonement, and it is not a general or universal atonement but limited to those God foresaw it being fit to predestinate. God's election was assured on the basis of the atonement, the atonement was materialized through an irresistible grace and this grace provided the strength to persevere. But because the latter three are false, the former is of no necessity at all.
Total depravity then falls as well (Thanks Jason). Because man is totally depraved, Calvinists say, then there was a need for God to elect some unto Himself, to provide the atonement which because of their depravity they could never attain of themselves, strike them with an irresistible grace so that they couldn't refuse it and give them the strength to persevere.
Man thus became an automaton serving no function of himself but solely at the bidding of predestinating forces which compel him to act in the way preordained. The Fall in the garden was not an emanation of man's free will but God caused Adam tom act and to bring sin into the world. He created the Devil predestinating him to rebel, to fall and to mislead the world including launching the persecutions that resulted in hundreds of millions of death.
All the world's a stage and we are all little marionettes with God pulling our strings.
Better yet, God is very much like I was at about seven when I put my little toys into fights and blew them across the room with my sheer imaginative power and imagined they were all my pawns for my central pleasure.
That is the Calvinist God and if that were true, He would literally have to force you with something as stupid as irresistible grace to follow Him.
Thomas Jefferson had a quote about this. I disagree with him on most of his religious views, but he has some of the most fascinating theological beliefs out of any historical figure. To me his beliefs are the most fascinating. This is what Jefferson said to John Adams on Calvin,
"I can never join Calvin in addressing his god. He was indeed an Atheist, which I can never be; or rather his religion was Daemonism. If ever man worshipped a false god, he did. The being described in his five points is not the God whom you and I adore, the Creator and benevolent governor of the world, but a daemon of malignant spirit. It would be more pardonable to believe in no god at all, than to blaspheme him by the atrocious attributes of Calvin."
Many of Jefferson's words must be read in light of the Enlightenment age in which he lived. His antisupernaturalism was common in that day and it lead him to compose his own Bible, the Jefferson Bible. He was a man of deep conviction who believed in an undying devotion to proclaiming the truth, though some of what he preached had come down to him in a polluted form. But he was a man of character and integrity who believed in a God of omni-benevolent character, though never quite determining who that God was.
I feel he was right about Calvin. As for the tendency for his soteriology to disintegrate, even if there were some degree of biblical support for his theories they might stand, but lacking that, and no consistent theory on which it may stand, it all falls. I feel it has done Christianity a disservice and I go along with Jefferson in declaring it a blasphemy, though I would prefer the term heresy and agree that the god of Calvin was more akin to one of Satan's kingdom, rather than the Father of Christ. This is the disputation against Calvinism.