Again one of the problems with choosing just one or two verses from the Bible out of context, not just within the chapter, but with regard to the Culture and practice of the time is that you can contort the meaning.
The Old Testament was written in Biblical Hebrew, not english. The practice of the Jews was to offer sacrifices and pray for the dead. Death is referred to in various places in the Scriptures as sleep. From that some Protestants, most of all the Adventists and Jehovah’s Witnesses believe that the person is unconcious, cannot be helped, and is unaware of anything until he is raised up again. We know this to be untrue with the story of Lazerus and the Rich Man. (Luke 16) The Rich Man was aware of his own surroundings, that Lazerus was in heaven, and that his 5 brothers needed to be warned to change their lives. While a bit off the topic you asked for, those who make the allegations you mention choose those verses that seem to support their positions while omitting the rest of scripture, or it’s context.