My interpretation of "once saved always saved' may be different and wrong but this is how I interpret it: Once you accept Christ's sacrifice for your sin, you are His and cannot "lose your salvation". You will go on obeying God and focusing on Him and others, trying to beome more Christ-like. I believe you can turn and walk away from God. It will be your choice to remain a christian while you are here. If you disobey and screw up though, you will not, because of it, lose your salvation. If you are trying and fail, it is OK. If you are not trying and doing wrong in the eyes of God, then you should probably ask yourself if you are really a Christian in the first place.
I think what you are describing is not an absolute "eternal security" outlook. As you stated, a person can
choose to turn and walk away. I think this is similar to what I said in that while Scripture indicates that
nobody can snatch you from Christ there doesn't seem to be a similar verse indicating that a person can't remove themselves from Christ's hand. I also agree that we can't know for certain the correct view, and while this difference may appear on the surface to be minor and/or simply semantics - I don't want to discount the difference either.
God knows our hearts. He knows where our loyalty is. He knows whether we are obeying or whether we are doing our own thing. One might look and sound like a terrific person/Christian and not be a follower of God. One may not go to church but yet walk daily, step by step with Him. It is all a matter of the heart, IMHO. You can't fool the Creator!
True, and this is where Justin Martyr originally (and where Karl Rahner recently) find support for their
Anonymous Christian view.
So, when gentiles, not having the Law, still through their own innate sense behave as the Law commands, the, even though they have no Law, they are a law for themselves. They can demonstrate the effect of the Law engraved on their hearts, to which their own conscience bears witness; since they are aware of various considerations, some of which accuse them, while others provide them with a defece... on the day when, according to the gospel that I preach, God, through Jesus Christ, judges all human secrets. Romans 2:14-16.
Paul witnessed Gentiles, for whatever reason, behaving as though they were following the Law (moral, not ritual) that God gave to the Jews - that somehow it had been engraved upon their hearts. Justin Martyr - and more recently, Karl Rahner - have postulated that perhaps the same can be said about the presense of the Holy Spirit. This thought is fuelled by individuals such as Ghandi, who was not a Christian, yet spoke highly of Christ's teachings and frequently exhibited in his own life, principles and behaviour that are at the heart of the Christian message.
I believe we can and should know whether we are true Christians and know if we have salvation or not.
As much as I am pretty strong on the atemporal view of God, I am also fairly in line with the Catholic teaching on salvation. Most Christians are familiar with the Doxology that says (of Christ) "Who was, and is, and is to come". The Catholic Mass includes as one of its Mysteries of the Faith, "Christ has died, Christ is Risen, Christ will come again". It's all a past - present - future thing. So, this spills into our salvation views: I
have been saved by and through Christ's sacrifice, I
am being saved as I follow by Christian walk through the guidance of the Holy Spirit, I
will be saved and be purified by God in the afterlife. For Catholics, salvation is a process rather than a singular event - and perhaps that is why (with our acceptance of full free-will) we are mindful of ensuring that we fully cooperate with the process and not stall or halt it through our own actions. The sins we commit, in and of themselves, are not enough to halt the process, unless they are done willfully with no intention of repenting - since that, in essence, means a person has chosen to reject God's love and forgiveness. That does not mean, however, that you are now lost. Denying Christ once doesn't mean that you are guaranteed damnation any more than accepting Christ once guarantees your salvation.
Of course, this always raises the issue of what happens to a person who dies when they are in a period of being a "backslider". Again, this is all stuff we just can't be certain about, but my hope is that upon death, and coming face to face with God, a person will once again repent sincerely and place their trust in a merciful God.
It is not a matter of waltzing into heaven all pious. It will always be a matter of knowing without Jesus' sacrifice you'd never go to heaven no matter how good you could ever be. Good isn't good enough. I suppose everyone would react like the man in Daniel when it comes to seeing God someday...on my face, on my knees, in awe and amazement. Even though I feel assurance I can promise you there is no self-righteous here. When it comes to God, I am on my face, grateful and overcome.
This is what I mean (somewhat) about being on my knees myself. As much as I know God's willingness to forgive, I just so often feel unworthy of that gift. Unfortunately, I think that there are Christians who are prone to the sin of Pride, and that they do take the belief in eternal security to it's improper extreme. I am always reminded of the lyrics to Peter Gabriel's song "Big Time" -
And my heaven will be a big heaven... and I will walk through the front door. The song is a condemnation of egotism and pride. When I die, I don't plan on walking through the front door. I imagine falling to my knees, and praying that God will pick me up, and carry me inside.
It is only MHO, but I do not believe that there are second chances after death. Personally, I think when anyone stands in judgement from God, they'll bow and say "There is a God" but it will be too late. Maybe (and it'd be nice) I'm worng but I would never give anyone a slight feeling of 'well, if I die and see there really is a God, I'll believe then" and mislead them into thinking there could be a chance after death. From studying the Bible, my guess is we decide here and now and we'd better not wait. After all, the journey with god in this lifetime is extrememly precious. I wouldn't miss it for anything!
Of course, both opinions are there - and we can't know with certainty the fate of non-Christians upon their deaths. I don't mean to mislead anyone by what I hope could happen. At the same time, I can also hope that in speaking of God having that much mercy, a person might want to think about what that means. Even if the person simply thinks about God having that much mercy (or thinking about God at all) is - at the very least - a step towards God.
Show me one person who follows every doctrine of Catholicism and I'll show you Pope Benedict XVI. I am a Catholic and I participate in my local Catholic community. Views like mine have been openly discussed, often with our priests, who surely are more qualified to determine who is Catholic than you. 
