There’s a lot going on in your post, but that whirlwind of competing ideas (not yours) about HOW a person is made right with God puts us in a real pickle. If baptism is when IT happens, and subsequent sins end us up back at Square One, why wouldn’t God just kill us as we come up from the waters?
Stupid, I know, but real people get really messed up by confused teaching. “I will have mercy on whom I will have mercy, and I will harden whom I choose to harden” is one my favorite bottom lines from God that blow up all the baloney about “merit”.
I have always said, if this is true, just drown me in the baptistry.
:-)