Revelation 2:26 (WEB):I think that's an unsupportable doctrinal claim. Context proves it.
(26) He who overcomes, and he who keeps my works to the end, to him I will give authority over the nations.
If we suffer from such deterioration of our minds and bodies at the end of our lives, then I guess we just have to trust God's judgement that He will not blame us for our loss of memory and reasoning power. My dad suffered from dementia, badly, so that he completely forgot who we were, and forgot everything he had learned - he couldn't speak and had the apparant intelligence of a very young infant. It was as if his mind regressed backwards in time to as he was shortly after being born. He even forgot that he had been a heavy smoker virtually all of his life, and just stopped smoking - something he had never done before! I considered him dead, as far as the person I used to know, while his body continued functioning for a few more years. I hope that I won't end up with dementia!A scary thought too. Many old people are suffering from dementia and other mental issues.
Might we lose our salvation due to that at the end of our lives?