Once Saved Always Saved - Preliminary Remarks

There are many good short articles and long books addressing the doctrine of eternal security, but none that I've found that work exhaustively through the Scriptures as it touches other doctrines. It's time to remedy that.
Let's begin with a more complete definition of what I'll be seeking to prove:

"They, whom God has accepted in His Beloved, effectually called, and sanctified by His Spirit, can neither totally nor finally fall away from the state of grace, but shall certainly persevere therein to the end, and be eternally saved.

The perseverance of the saints depends not upon their own free will, but upon the immutability of the decree of election, flowing from the free and unchangeable love of God the Father; upon the efficacy of the merit and intercession of Jesus Christ, the abiding of the Spirit, and of the seed of God within them, and the nature of the covenant of grace: from all which arises also the certainty and infallibility thereof.

Nevertheless, they may, through the temptations of Satan and of the world, the prevalency of corruption remaining in them, and the neglect of the means of their preservation, fall into grievous sins; and, for a time, continue therein: whereby they incur God's displeasure, and grieve His Holy Spirit, come to be deprived of some measure of their graces and comforts, have their hearts hardened, and their consciences wounded; hurt and scandalize others, and bring temporal judgments upon themselves."

I know, I know. You Calvinists are thinking, "What are you doing, perseverance of the saints is the appropriate title!" To which I say: I don't like the TULIP acronym, and anyway this series is for skeptics, or the fence sitters, and those people are going to argue with me no matter what I call it. You might think that by calling it perseverance of the saints you can head off a potential objection, but I have not found that to be the case. So I'm calling it "once saved always saved" because it's both true and I think better highlights the eternality of the moment of faith. In this series I'll be channeling Matthew Henry by pointing out that the verses mean exactly what they say, and John Owen by working so extensively that by the time we reach the end the reader will feel as though the matter was settled. 

One more thing: there are a number of good and logical arguments we could make to prove the doctrine, but I'll skip on those. Instead, in this series, we'll be looking at only what the Scripture has to say about the topic, and making our judgments based on that alone.
So enough talk, let's get to the good stuff.

Next: Part II - Not Upon Their Own Free Will