How will you explain to your children...

[Cinjin]

In a world where there's no scientific proof of God's existence and of life after death how will you explain to your children why you brought them into the world and why they will have to die?

You do realize that this question contains a massive non-sequitur.
The question of whether or not god exists has nothing to do with why I decided to have a child. You are implying that most people bring children into the world for some higher existential meaning and that we all have some kind of unexplainable duty to burden our children with religious and philosophical babble about our place in the universe.

Your entire argument is utterly ridiculous. It goes something like this: Tell your children the same stuff that I was told as a child because in my mind, it's important for some unknown reason to explain the universe, death and the afterlife in a nice neat tidy little sentence.

When in reality, if you left a child alone to be a child and simply grow up without all your superstitious horse shit being heaped on him, he'd have a much better chance of being a rational, well-adjusted human-being worthy of leading others into a better future.