in theory, if we're able to upload peoples minds into a computer, how would that allow them to live forever?

>brain is uploaded to a computer
>doctor: okay sir you're all done
>afraid2diefag: wait i thought I would live forever why am i still in this skin suit
>doctor: no but we downloaded your brain patterns into our machine

we also have not solved the issue of complexity, if we are bio machines, it would be impossible to understand our own minds, we would need to rely on black boxes due to the complexity beings impossible to comprehend.

final point is, if we're all le internet atheist, what is the fear of death? would it not comfort you to know that your mind is just creating fear and discomfort in your mind as a instinct to preserve itself, and in reality you're just matter which tricked itself into thinking its something greater, the religious concept of death and punishment are much more terrifying.