Just to say, for any who might wonder, I do believe in eternal security. Scripture is full of promises that God will never cast out his faithful children or change His mind about His salvation. "I will never leave thee nor forsake thee" cannot be any firmer either in the English, or in the Greek from which it is taken. Psalm 23 ends with the promise, "Surely goodness and mercy shall follow me all the days of my life..." and begins with "The Lord is my shepherd."
What causes problems with some people, though, is not eternal security, but eternal presumption. Eternal presumption claims the Lord as his shepherd, but insists on shepherding himself. When he hears the Lord calling, "Follow Me" he imagines he also hears, "..and you can take the lead," or, "wherever you want to go." We preach that Christianity is a relationship, but do we then exclude Jesus from the picture? We say that Christianity is a party, but is it Jesus' party we're going to, or do we somehow throw a party in His honor, but leave Him off the guest list?
Here in America, the polls tell us that 85% of the people are Christians, most of these claiming a "born-again" experience. Jesus gave us a parable, in which the Word of God was eagerly received, and imparted life and promise, but from it not being allowed to take root and assume its rightful place as a plant growing in the soil, the life and the promise died away. The ground where it had been planted then became dried and hardened, covered with obnoxious weeds. Consistent with that picture of God's Word being like a seed, Paul writes, "..if anyone be in Christ, ..all things are made new." The Christianity of that 85% has so little effect on their own lives that militant atheism and a "rights" agenda aimed at turning the world into a homosexual "paradise" (both representing a scant minority in the US, have them cowed to even mention the name of Christ in public. Like the withered seed, they have no power, no confidence or joy, their lives do not make a difference because their lives, for the greater part do not differ from the "norm" of the non- Christian "minority."
King David, in Ps. 19, speaks of two kinds of sin that can affect our lives. First, there are "errors" and "secret faults." In the Law, these sins, when discovered, could be atoned by some kind of sacrifice as a kind of "personal housekeeping" to keep things right with God. Also, there were the "presumptuous sins." Presuming on God's mercy and "niceness," violating God's commands and principles regardless. Even in the New Testament there is no blank-check guarantee that this can be forgiven. In Hebrews we read, "They that sinned knowingly under Moses' law received no more sacrifice for sin, but a fearful looking-for of wrath and fiery indignation." and, "How much worse punishment, do you think, will be deserved by the one who has spurned the Son of God, and has profaned the blood of the covenant by which he was sanctified, and has outraged the Spirit of grace?For we know him who said, "Vengeance is mine; I will repay." And again, "The Lord will judge his people." It is a fearful thing to fall into the hands of the living God."
Is it all hopeless? Not necessarily, but as the Spirit continues in that passage, it is on us to remember the goodness of the Lord, call on Him, and commit our lives to being His people, on His terms, rather than presuming that He is ours, on ours.