I believe Jesus shed His blood for me and all my sins - past/present/future because He understands that the stiff-necked folks who insisted on the Commandments had served to prove that none of us could ever be worthy in and of ourselves. And when God told us that there would be a time of a New Covenant where a man's sins would not be visited upon his children, men would have knowledge of His existence written in their minds and hearts, and that He would forgive their wickedness and recognize their sins no more, He was speaking the Truth and He followed up by sending Jesus to pay our death penalties that we might be made worthy by His actions.
>>>So, some folks will be saved but “not saved enough” for the Rapture to take them.<<<
Exactly.
Luke 21:36 Be always on the watch, and pray that you may be able to escape all that is about to happen.
Hence, some (believers) will not be on the watch and will not escape (the Tribulation).