I just ran across one of those instances of “forever” in I Mac 14: 41 which seems to clarify the matter with respect itself, anyway:
“And the Jews and their priests decided that Simon should be their leader and high priest for ever until a trustworthy prophet should arise…”
So, in the case of a person, “forever” would certainly be limited to their lifetime, and this verse indicates another restriction (which is hard for me to understand–it doesn’t say what effect this trustworthy prophet would have).
So, here, “forever” seems to mean “for life” but when one says “forever” it is 1) simple hyperbole, 2) an attempt at flattery, 3) an attempt to sound “biblical,” etc.
When it comes to those other instances (i recall generally what you’re saying) of course we know the end of the story so it is natural to question what “forever” means. The answer of the Bible is 4) until God changes it. If Israel fails on its end of the covenant, the ballgame is over until God returns to reestablish a new covenant.
Yes, i generally agree that Jesus is the fulfillment of “forever” because “forever” does not specify how God will accomplish that. Jesus accomplished what mankind could not.
Thanks. Interesting question (for the scholars of which I am not). “The New is concealed in the Old.” So, Jesus is perhaps concealed in those “forevers.”