The "T" refers to total spiritual inability and that assertion is unbiblical. Matthew 13:20-22 teaches that unregenerate folks have the ability to accept the gospel with joy, so while some folks have hardened themselves with the practice of sin, they have lost what spiritual ability they had, and therefore cannot understand the gospel, this condition does not apply to all men, according to Jesus.
On the contrary, the "T" refers to
moral inability and that assertion is utterly Biblical. The basic assertion is that even our best righteous actions or thoughts or wills are corrupted by our sinful nature.
Therefore you have no excuse, O man, every one of you who judges. For in passing judgment on another you condemn yourself, because you, the judge, practice the very same things. We know that the judgment of God rightly falls on those who practice such things. Do you suppose, O man—you who judge those who practice such things and yet do them yourself—that you will escape the judgment of God? Or do you presume on the riches of his kindness and forbearance and patience, not knowing that God’s kindness is meant to lead you to repentance? But because of your hard and impenitent heart you are storing up wrath for yourself on the day of wrath when God’s righteous judgment will be revealed. Rom 2:1-5
What then? Are we Jews any better off? No, not at all. For we have already charged that all, both Jews and Greeks, are under sin, as it is written:
"None is righteous, no, not one;
no one understands;
no one seeks for God.
All have turned aside; together they have become worthless;
no one does good,
not even one."
"Their throat is an open grave;
they use their tongues to deceive."
"The venom of asps is under their lips."
"Their mouth is full of curses and bitterness."
"Their feet are swift to shed blood;
in their paths are ruin and misery,
and the way of peace they have not known."
"There is no fear of God before their eyes." Now we know that whatever the law says it speaks to those who are under the law, so that every mouth may be stopped, and the whole world may be held accountable to God. For by works of the law no human being will be justified in his sight, since through the law comes knowledge of sin. Rom 3:9-20
From of old no one has heard
or perceived by the ear,
no eye has seen a God besides you,
who acts for those who wait for him.
You meet him who joyfully works righteousness,
those who remember you in your ways.
Behold, you were angry, and we sinned;
in our sins we have been a long time, and shall we be saved?
We have all become like one who is unclean,
and all our righteous deeds are like a polluted garment.
We all fade like a leaf,
and our iniquities, like the wind, take us away.
There is no one who calls upon your name,
who rouses himself to take hold of you;
for you have hidden your face from us,
and have made us melt in the hand of our iniquities. Is 64:4-7
The quote of Mt 13 is a poor prooftext, being out of context. It states that people who do believe
something about the Gospel (probably a belief that it is good news) celebrate it with us for a time, but then drop out. Calvinists argue that they're clearly unregenerate, all the way through. They don't become regenerate, then unregenerate.
The "U" refers to Unconditional election and that assertion is unbiblical. God chooses folks based on their characteristics, he credits their faith as righteousness. James 2:5, Romans 4:5.
On the contrary, Scripture talks directly about God being the One Who chooses, and that not based on human will or effort.
though they were not yet born and had done nothing either good or bad—in order that God’s purpose of election might continue, not because of works but because of him who calls— she was told, "The older will serve the younger." As it is written, "Jacob I loved, but Esau I hated." What shall we say then? Is there injustice on God’s part? By no means! For he says to Moses, "I will have mercy on whom I have mercy, and I will have compassion on whom I have compassion." So then it depends not on human will or exertion, but on God, who has mercy. Rom 9:11-16
Rom 4:5 isn't relevant because it's understood in Calvinism that belief is the characteristic of someone with a changed heart. The person's already been changed from the heart. Changed by whom? Himself or God? "
circumcision is a matter of the heart, by the Spirit, not by the letter. His praise is not from man but from God." Rom 2:28
James 2:5 is misquoted. God picks people for salvation without respect of characteristics. Many are poor, and that teaches us something about respecting the poor as our family of Christ. Some are rich, and that teaches us something, too. They're not special -- they have tasks to do, too. "
As for the rich in this present age, charge them not to be haughty, nor to set their hopes on the uncertainty of riches, but on God, who richly provides us with everything to enjoy." 1 Tim 6:17
God didn't choose poor people exclusively nor inclusively. He simply chose people. He chose the poor to teach
us something -- in fact the exact opposite of, "It's clear why God chose him to be saved, because he's [poor|rich]". To miss that is to miss what James 2:5 says.
The "L" refers to Limited Atonement and this assertion as defined by Calvinism, is unbiblical. 1 John 2:2 tells us Christ is the propitiation for the whole world. Christ laid down his life as a ransom for all.
On the contrary, Calvinism speaks of Atonement in terms of who is actually atoned-for -- who Jesus lays down His life for. In other words, the Atonement is an actual atonement. The Atonement is not a proposition about salvation. The Atonement is the entire process of salvation.
I am the good shepherd. I know my own and my own know me, just as the Father knows me and I know the Father; and I lay down my life for the sheep. John 10:14-15
So not everyone is saved. Were the ransom paid on all, all would be saved.
Jesus is the sole One propitiating, as 1 Jn 2:2 states. He's
for this whole creation. But
He won't save every person in this creation. And that's precisely what the doctrine of Limited Atonement says.
It may be instructive to point out, in free-will views Limited Atonement isn't expanded to Universal Atonement. It's still limited Atonement, though in a very different way. Why? Because in these views Jesus doesn't actually save anyone. Their wills or actions must be applied to His work to finish the actual Atonement. So the Atonement is partial.
The "I" refers to Irresistible Grace and this assertion is unbiblical. Matthew 23:13 teaches us of folks who were entering heaven, and thus, according to the false doctrine of Calvinism, were under the influence of Irresistible Grace, yet they were turned aside by false teachers.
On the contrary, Irresistible Grace is the attribute of creative grace. You can't stop God from creating a new life within you. You've no force in the matter to exert. Ep 2:1,5 describes this case: "
even when we were dead in our trespasses, made us alive together with Christ— by grace you have been saved"
For while we were still powerless, at the right time Christ died for the ungodly. For one will scarcely die for a righteous person--though perhaps for a good person one would dare even to die--but God shows his love for us in that while we were still sinners, Christ died for us. Rom 5:6-8
Why Mt 23:13 would be relevant in this case is a paradox. It certainly doesn't speak about God's power to create spiritual life. In Mt 23:13 Jesus is attacking the severe inconsistency in the Pharisaical view of the kingdom of heaven being the kingdom of Israel, of setting high bars to a counterfeit of the kingdom of heaven, deflecting people from entry into that. Of course this obscures the true kingdom of heaven, and the Pharisees are accused of deception and deflection. God ordains the processes of His creation (theologically, "means"). The Pharisees were subverting them.