The gist is that you have up until you die to accept him even after denial as long as its before your death you are still free to go either way.
Let me get this straight. After we die, we either go to hell or we go to heaven, right? And in both cases, it's forever, right? But I'll have to acknowledge God before death, to get into heaven. So, based on an infinitessimally short portion of my eternal existence (doomed or saved), it's decided which way I go. Not only that, but it's also at the very beginning of my eternal existence, when I cannot reasonably be expected to be as wise as I would be after, say, a few million years in heaven. It's like asking a toddler to decide what it will do with its life, the first milisecond after it has spoken it first word. Sounds hardly fair to me.
"It's amazing what you can learn from DNA." - Desdamona.