I believe what is meant, Hiskid, is that God (and heaven) exist ‘out of time’.
Ok, so here we are right now in 2010, right? Suppose we say a prayer for somebody (maybe a grandparent) who died in 1970, 40 years ago.
Now --this is the thing. Obviously, when the grandparent died (40 years ago), at that very time (the minute of death) the grandparent either chose heaven or hell, yes?
That has not changed.
BUT. . .in Heaven, and with God, God Himself did not experience 1970 as a ‘time’. God exists out of time. God, right now, is not sitting up there in heaven saying, “Well it’s August 30, 2010, better get out the day planner and get ready to change the calendar to September the day after tomorrow”. . .
IOW, God hears our prayers ‘today’ (we experience this as August 30, 2010) but God is hearing them in an eternal kind of ‘now’ just as He experienced hearing our prayers last year, the year before, the year before, 40 years before. . .
IOW, God is hearing our prayers in an eternal NOW and He hears all our prayers in this eternal now.
The prayer of the grandparent 40 years ago. . .the prayers of the people living 100, 500, 1000, 10,000 years ago. . .are all heard in that same eternal now.
THAT is what is meant by applying prayers. We don’t think we go ‘back in time’. We think that since God hears all prayers kind of ‘at once in an eternal now’ that prayers that we say NOW are heard at the same ‘time’ (so to speak) as prayers said by people 100s and 1000s of years ago. So indeed, even while our grandparent was dying 40 years ago, our prayers today might have helped him (BEFORE that instant of death) to repent, even though we’re saying those prayers years ‘after’ the event.
Does that help explain? It’s not that we go ‘back in time’ ourselves but that God hears everything in a kind of ‘time out of time’ that is the same for all people at all our ‘temporal’ times.