I sure hope so.
But do you have good reason to believe so, especially in light of the fact that you (like everyone else in the world) have new thoughts and new beliefs periodically, regardless of what you want?
I hate tjhe ide athat I hav esome external demon (for lack of a better word) cosntantly fucking with me.
Why do you verbalize it as an external demon? The reality is that we are emergent properties of the elements of this world and that changes in the world can result in changes in us. You're not describing someone comitting a metaphysical crime against you, you're describing things happening.
You know what I would find horrifying? Being a subhuman automaton that never changes. Which, as mentioned above, you could not achieve even if you wanted to. You could become a Buddhist monk and only ever meditate and sweep floors for the rest of your life, and you would not achieve that.
We are subject to conditions. There is not a choice that you or anyone else can make that will change that. But we can make choices that can change how we suffer, and what else we do besides suffer. I would rather suffer how I wish, and do as much else as I can besides suffering. Thusly, change is absolutely necessary, not only for life, but to approach irreplaceability.
Your course - to change as little as possible - is the opposite. By reducing yourself merely to certain passions, relationships and convictions, you are making yourself more replaceable.
Please avoid portraying what I have said as faithlessness or disregard or lack of convictions in your response.