Roughsoul, I admire your search for truth. There is so much contrary opinion, even among believers. Here we are 25 pages in and still nothing conclusive for you. I became a Christian at age 22 and sought truth exhaustively ever since. Hours a day I spent learning as much as I can to answer the nagging questions about who we are and who God is and the relationship between us. I'm fairly certain that you can't ask a question that I haven't already asked and received answers for. The problem is that truth cannot be reduced to a handful of Bible verses. There is a Truth that is the Rosetta Stone of Christianity that explains everything, and I mean everything, past, present and future. I don't challenge the authority of Scripture but I will say that it is incomplete, not in substance (I don't want to be accused of adding or taking away), but for explanation. We take a couple verses out of context and build a theology from it. You have to read and incorporate the whole thing. That's why there is confusion. As far as once saved always saved this is what needs to be considered; Christ's sacrifice is a gift. There is two parts to a gift giving, the giving and receiving. He gave the gift to the whole world! Only some accept the gift. You can't earn a gift. This is where the confusion is. You can't do anything to make yourself more or less deserving of the gift. What you do with the gift will either make you child of God or not. The gift is free but it has strings attached. It might be like a parent giving a teenager a brand new car. Then the parent says, "This is your car but know that if I ask you to pick your siblings up or go to the store, I expect that you will, without arguing." The child didn't earn the car, but it comes with expectations.
Some people are willing to accept the gift of salvation but unwilling to fulfill their end of the bargain. You cannot be a child of God and live like a devil. It is the act of living in the spirit that transforms us. We actually become a new creation. We become more aware to the fact that the body is just a shell and that our essence that becomes acceptable is no longer subject to the demands of the shell. The shell has programming created by God. The programming is to work, adapt, survive and procreate. The programming got hacked! The Spirit is like a system restore and causes us to regain control over the shell. This allows us to serve Him. If we make Him our Master than we become slaves to righteousness. If we continue to serve our shell and obey the desires of the flesh, then it becomes our master and is incapable to do anything but die. Our spirits are designed to inhabit a shell. Since the Creator is capable to create us a new body, this will be our reward at the resurrection. All who serve the flesh will die and their spirits will continue to be absent from a shell and therefore be in eternal unrest.
As far as the elect is concerned, He predestined from the beginning that there would be a group of people that would follow Him. He doesn't pick and choose who is worthy to be selected.
Romans 8:29-30Holman Christian Standard Bible (HCSB)
29 For those He foreknew He also predestined to be conformed to the image of His Son, so that He would be the firstborn among many brothers. 30 And those He predestined, He also called; and those He called, He also justified; and those He justified, He also glorified.
I believe that this refers to the entire Church, meaning that He established from the beginning that man would fall, He would be the One to call His people (He sought everybody, called), Christ would come for redemption (justified) and an elect would be glorified in the New Age (glorified).
If you are His and He is your Master than salvation cannot be lost. All you have to do is take a look at your life to determine who your Master is. Who are you serving? Is your time spent seeking His will and loving others? Is your money spent on comfort and pleasure or furthering His kingdom? Do you spend more time on your hair, than on prayer in the morning? How much time do you spend in prayer for other people? When you sin, do you make a confession or an excuse? Do you talk to God like He is your Father or a stranger? From the answers to these questions you should be able to determine whether He is your Master and Father.
But, certain events happen and their belief may fade for awhile. Then when they "see the light" at the end of their hardship, their belief builds back up again.. I can say with absolute certainty, that everyone here has stopped believing (temporarily) at one time or another in their life. And by that, I mean maybe certain bad things caused them to stop believing for awhile, and then they realized their situation wasn't so bad after all, so they started being able to see God in the mix and started believing again. 
