This is a huge topic, and I don't know if anyone can be sure they have a complete knowledge of the truth of this. A person could be convinced that it is possible or impossible to lose your own salvation but as they mature in understanding and experience of God over time their view could change.
It is our duty I think to study the bible to see what it says on this topic, from what I have read on this 'thread' a lot seems to hang on the interpretation of certain verses and passages, the bible does need to be taken as a whole and verses must be read in context or we have distortion of the truth that was intended for us.
Maybe that's why the bible teaching on this subject is somewhat fragmented - so that we could with the help of the HolySpirit come to our own conclusions as we study His word and try to live it out. Yes even living before God in fear and trembling and adoration and worship.
A housemate of mine was wondering about this and she hasn't come to a conclusion, and I havent either, somehow I think both are true - we are eternally secure, our salvation doesnt depend on us, we were regenerated by God if you study 'regeneration' you will see that our own response in conversion was due to God's sovereign work. I suppose you could argue that if God intended us to be saved by His own irresistible work then He is sure to keep us in the faith and has every intention of doing so - and who can resist his will.
Romans 9 addresses God's sovereign purpose in electing some and not electing others for eternal salvation. Sobering but true.
At the same time the bible is full of encouragement, instruction to be holy and dire warnings. It isn't a salvation of works and yet we are required 'to work out our salvation with fear and trembling' there is one work if it can be called a 'work' the work of faith which is in turn inspired by God, yet we are required to continue therein.
People can use the 'once saved always saved' slogan as an excuse to live however they please, and that I believe is a dangerous way to live, but we are called to live in order to please God, if you are truly regenerated then you will desire to live a life pleasing to God and when you sin which you will - you will likely feel terrible and run back to your saviour in full repentance - that is how true believers really feel...
