Quite honestly l see no difference in eternal or everlasting or life without end etc . These divisions seem to have been made up by the WT . Looking at the Bible as a whole l don't see any evidence for a two tier system .
Where does Jesus, Paul or any of the other writers say " this teaching is for this group , not for that group " ? All the same teaching was given to everyone. Paul boasts that what he received from Christ is exactly what he passes on to ALL the followers.
These complications are just WT inventions to keep JWs in line and faithful. They feed the distrust of mainline churches who ' have it wrong '
That's my take on it .
Jan