1st Peter 4:6:
For for this cause was the gospel preached also to them that are dead, that they might be judged according to men in the flesh, but live according to God in the spirit (KJV)
Who are the dead ones here? Are they the dead believers (Christians) or just anyone dead?
What kind of gospel had been preached to them? Was it the good news reported about Jesus' death and resurrection or was it something like the promise of the grace of God to come like in 1 Peter 1:10-12 ("Of which salvation the prophets have enquired and searched diligently, who prophesied of the grace [that should come] unto you. Searching what, or what manner of time the Spirit of Christ which was in them did signify, when it testified beforehand the sufferings of Christ, and the glory that should follow. Unto whom it was revealed, that not unto themselves, but unto us they did minister the things, which are now reported unto you...")?
When had the gospel been preached to them, while they were still alive or while they were already dead?
What was the purpose of preaching that gospel to them? It says "that they live according to God in the spirit". In case they were already dead while the gospel was being preached to them, how could they live according to God in the spirit while being dead? Does that mean that there is still a way of living somehow in the spirit even after one's physical death?
What are some possible interpretations of this verse that are allowed by the text itself (I mean without any admixture of any doctrine that is not based on the text)?