If all knowledge of the Earth was erased?

When asked what one book he would want to have with him if stranded on a deserted island, G K Chesterton answered "Well, 'The Practical Guide to Ship Building' of course."

The point of quoting Chesterton here is to simply point out that he was a devout Christian who was himself an insanely practical man. I am of the opinion that true Christians are among the most practical of all people. But practical doesn't translate into anti-religious or anti-God. The conclusion we are supposed to come to with regard to your question is that religion is not among the things that are really important to our survival. If my memory serves me correctly, I read a similar argument from Sam Harris (in "The End of Faith".. or it may have been "Letter to a Christian Nation", not sure). The idea is that pragmatic concerns will out pace religious concerns hands down. There is a great deal wrong with this far too simplistic assessment. But rather than get into that, allow me to quote Chesterton again.

"Pragmatism is a matter of human need, and one of the first of human needs is to be something more than a pragmatist." from Orthodoxy by G K Chesterton

That time is destined to happen. The Hindus have a saying 'All things must pass.' And the Zen Buddhists say 'When all is gone, and not even a blade of grass or a grain of sand is left, there will still be zen.' By that they mean zen is not a thought or a concept, it is beyond that - it is the natural law of the universe.

But we puny mortal bodies don't have to be concerned. Time will regenerate everything.

Will we ever want to reinvent the mythologies and cosmologies of religions like Islam and Christianity? Maybe. But it will be more fun and interesting to create new religions.

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If all knowledge of earth was erased would we even know we are living on the planet earth?

Huh!? What on EARTH are you talking about? How would we know "when" we would want to learn things that we would know nothing about? What is the significance of those things you listed? Im so lost on this one, your question makes nary a bit of sense.

Sorry.

My brain turned off while reading this...try a little rewordery.