The prodigal son is an excellent parable of such. He squandered his inheritance, but never left his place in the family.
It's somewhat odd that proponents of losing salvation never seem to provide any personal testimony about themselves losing salvation and their subsequent formula's for regaining it, and how many times they may have turned through this supposed cycle. In my own zealous "sin hunting" to completely snuff out any whiff of "external sin" I eventually landed on the fact that my own thoughts were the real problem. Was I saved or not? And I learned in that to destest formulas for supposedly "regaining" same, as it was a very vicious mindset. It was kind of like, the harder you try, the more frustration is encountered, and eventually you end up closely examining the sources of sin, and find it to be, just as scriptures denote, an internally sourced problem. I had to confront the fact that I could not make a Perfect Decision, and in fact I really don't even know what that might mean anyway. I am simply not GOD.
And in that process, I found that submission to My Perfect Father was the only option remaining. Submission is not a bad place to go, it's the only option. I, personally, went through this exact process that Paul speaks of here:
Romans 10:3
For they being ignorant of God's righteousness, and
going about to establish their own righteousness, have not submitted themselves unto the righteousness of God.
Initially, in my zealous "born again" experience, it was me and Jesus. But not long after, I learned that it was not me and Jesus. It was only Jesus. And that was my own submission. I prefer my "self" to be out of the picture, as I am obviously not big P, Perfect. I contemplate with God on this exact manner, early and often, looking for His Perfect and submitting to the fact that my own courses are and have proven themselves to be very much "out of my hands" and "control." I doubt very much that Joseph thought, in his initial bragging in front of his parents and brothers, in his dream of them bowing before "his sheaf"
entailed him being sold into slaveship in Egypt. But God came through, big time in a big way, when Joseph was a SLAVE. Even being in this present world is a picture of us all being "in Egypt." That was the course set for Joseph. It is "in Egypt" that Israel grew. Such nice pictures.
This has led to some wonderous matters in my life, that I would have never expected to transpire in a million years. God brought me into some very interesting situations and even more interesting predicaments where I did not have any answers. None. I was "worked out" and "finished" from my end. And then showed me what Grace was all about. It's helplessness. It's weakness on our part. It's unmerited favor, emphasis on the "un."
It's Trust. No theology formula ever spared me from His Hands.
And when one mountain of difficulty was passed, another, multifold larger obstacle, was already being setup in front of me. This can be an extremely frightening experience, but these things do tend to reveal Gods Very Firm Hands on things. The last thing I would consider is to try to "work my own way" into heaven. It's simply not possible for me to do that.
Hebrews 12:
7 If ye endure chastening, God dealeth with you as with sons; for what son is he whom the father chasteneth not?
8 But if ye be without chastisement, whereof all are partakers, then are ye bastards, and not sons.
9 Furthermore we have had fathers of our flesh which corrected us, and we gave them reverence:
shall we not much rather be in subjection unto the Father of spirits, and live?
It is exactly when we see that "our power" is gone, that God Steps In. And that is simple faith. Not something I am even capable of conjuring up.