Well from what I can gather of your posts you say things like,"the present believer" and other such phrases indicating that you believe one can lose salvation and thereby must maintain one's own salvation...
It's strange how people are saying that when we first believed 'having to believe in order to be saved' was not us trying to save yourself, yet we had to do that to be saved, but 'having to continue in that exact same believing to be saved' is now considered us trying to save ourselves.
That doesn't even make sense. If my believing when I first started it was not a work of self righteousness
then it isn't now. Believing is NEVER on the side of the works that can not justify in the Bible. Never. But the church has put it over there in their misguided zeal to preach Paul's warning about the works gospel.
...but I have a more simplistic question,"can someone believe wholly upon Jesus and then later on not believe upon him at all"?
Well, I have said this is the core question of whether OSAS is true, or not. The Bible is clear what will happen to people who do not trust God for salvation. That's not up for honest debate. What isn't so clear is if genuine believers can truly stop believing. I think it's possible because of how the warnings for believers to not stop believing are worded. And I know of Spirit-filled people who have abandoned their faith and by their own admission do not believe anymore. But I definitely fall heavily on the side of the argument that the warnings to not fall away are sufficient to keep the vast majority of believers believing and, therefore, saved.
...and to be clear I said believe upon not believe in,two different phrases with different meanings.
That is very clear. I make the distinction by often using the word 'trust' when referring to true believing. That is the faith that saves--the faith that is trusting God for the forgiveness of sin.
The demons do not have that faith. They only know the gospel is true, that's all. They certainly are not trusting in the gospel that they know is true better than you and I know it's true. Demons are neither trusting nor working to be saved through a knowledge of the gospel. And truthfully, that's how I would describe most people in the church today. They only have the faith of demons--the faith that James says can not save. It neither trusts nor works. I don't even know of anybody in the church who is working to save themselves. That message is thoroughly understood by the church, but it seems to be the favorite source of sermon material for pastors and wannabe pastors. What isn't so well understood by the church is the Bible's exhortations to continue to believe, but no pastors make that the topic of their sermons.