Calvin, among his other points starts with the point that we are totally depraved and sinful from birth. What is the Biblical basis for this point?
One thing to consider is that the doctrine of unconditional election goes hand-in-hand (logically) with the doctrine of total depravity. To establish this relationship, there are several passage to consider. The idea being that through sin, man is naturally "dead," and so predisposed against choosing the good news of God's salvation such that, left to his own devices, man won't believe and accept the free grace of Jesus's redemptive work.
Here is one passage, where one has to kind of read between the lines a bit is (emphasis mine):
Bearing this in mind (i.e. we were once dead, but we've been made alive), it's also interesting to note that reconciliation occurs at the point where man is still in emnity with God:
...and kind of along the same vein, this verse touches on the the heart of belief with a sort of tautology:
So if we think about the nature of belief, then this one should be a bit obvious, but it raises an interesting question. We only believe that which we believe to be true (the obvious part), so what would it take to suddenly believe that which one considers folly...and all the more a folly offered by one's enemy? In other words, if someone is an enemy of God (which we are before we're reconciled), and we believe the gospel to be folly (which we do before we believe it to be true), then how does one swap from a state of disbelief to a state of belief?
Ezekiel answers this question ... it takes a (quite literally!) change of heart:
This is regeneration. None of this would be necessary if man we already predisposed to be in harmony and faith with God, but since he's not, it requires a spiritual intercession to to soften man's heart. He is born again, and given the capacity for faith. This is the birth by spirit described in this passage:
This is also described in this:
Titus is particularly significant here, because it actually identifies the regeneration and renewal of the Holy Spirirt as the means through which salvation is extended.
So, in summary, Salvation occurs by grace through faith, and is applied by the regeneration of the Holy Spirit. This regeneration is the (nec.) second birth which gives those dead in their sin a new life with a new heart with which they are able to believe. This regeneration is nec. because the old, stoney heart of sinful man is, otherwise, unable (universally unwilling, if preferred :) ) to believe on the perceived folly of the gospel of grace presented by God (with whom man is at odds).
While I agree with warren's answer, I do believe like Ray points out that this is mostly about the original sin, transmitted from Adam to all of his offspring.
Total depravity goes beyond that, as it states that we are not only sinners, but that we are not even righteous enough to accept Christ on our own.
On the fact that all have sinned, we can refer to Romans 3:23, KJV:
and on the fact that we are not able to deserve salvation by our own efforts, you can see Titus 3:5, KJV:
This is a good place to start:
Btw, the Hebrew for "polluted garment" is more literally "menstrual rag".
But I think there is a lot of misunderstanding about total depravity. The Heidelberg Catechism has this to say about what it means to do something good:
And who would argue that natural man can do anything that fits that definition apart from grace? Here is the Canon of Dordt on the topic of total depravity:
If you simply delete the word "regenerating" from that article, you get something that both John Wesley and Thomas Aquinas could agree to (because of prevenient grace).
Understood this way, total depravity is not a "Calvinist" doctrine but one affirmed by the whole western church (the Eastern Orthodox have a distinctly different understanding of original sin). It only becomes Calvinist-specific when you start arguing over prevenient vs. regenerating grace, which to me seems like a pretty minor issue.
and Psalm 51, especially verse 5
are generally the first references for the doctrine.
God's reason for destroying the world with water in Genesis via the flood was that "the imaginations of the heart of men are only evil continually".
If there are "none righteous", and we are "brought forth in iniquity", then we have already failed to keep God's holy standard, and are, therefore, depraved from birth. If we are depraved from birth, and we cannot do righteously, then it is throughout the totality of our being.