Well SM has beaten me to a few points....
You see when we look at Faith, its not a case of Atheist or Religious... you have the Flat Out Atheist who defy Religion and Faith unless God came down and Greeted them but then they would pass them off as Alien beings or something else.
Then you have the Hard Core Religious who no matter what Proof to the contrary will always believe there was a Divine Creator who created everything.
So we Have Hard Core Atheist (Black) and Hard Core Religious (White) but there is a whole lot of Grey between those lines... and i think Shaw fits in the darker shade of Grey.
You could say Shaw was silly because of her blind Faith, and a Scientist but then what about Weyland?
He funded a Trillion Dollar Mission just as Fifield said "because of a Map you Two Kids found in a Cave"?
Shaw said not a Map and Invitation... she does not know this for a fact, but she believes its the case due to the amount of more than coincidental evidence she and Holloway had found... if we go back to the discovery of the Cave Painting Shaw says "i think they want us to find them"
She thinks this because of the clues they have found, and she is interested to see if these clues lead to any beings and if these beings or being are God.... She thinks its a invitation because you have to remember her FAITH she would see God as a Almighty Benevolent Creator who created Mankind as a favored Children, her faith is that God is not Evil... she said this when she said "god would not try and kill her"
So this is why she thinks its a invitation.... as for Holloway he would be wondering why would these beings leave clues to the same location and he may be naive to think it would be a trap....
It could have been a Benin Reason, and as such a Warning but then maybe you would think it would have been more clearer... i.e Ancient Beings who was trying to Warn us would have left a bit of clues that would lead to a threat?
I think they could be simply the Engineers showing where Mankind came from, we know the Engineers are not from LV-223 but from Paradise... so i think LV-223 was just some Greenhouse/Nursery that these Genetic Gardeners use to create and experiment with Lifeforms and when they have the desired results they then seed them on Earth.
I think they showed us this is where you came from... maybe the Engineers would never intend for us to be as Advanced to ever be able to reach as far as the Stars, they was in their Arrogance very Naive about how far we could Evolve without their help.
Back to Weyland we have to ask why did he blindly fund a mission based on this two kids star maps?
Well the Weyland Files etc shows us more, they show us that Probes/Sensors had detected a System in the Zeta 2 system that could support life... (life supporting environment) and the company intended to journey there at some point.
To then latter detect a signal, would all seem to much of a coincidence for Weyland and so he felt there was nothing more he could lose...... if this place is where the Gods came from maybe they could give him more Life.
But just based on a hunch, why risk all of that? Depend on the Character, we have to remember Weyland appears as a Selfish Man only cares about his own success and such people when faced with death (we get them in real life) would rather squander there fortune in a hope to extend their life, than accept the inevitable and leave their fortune to their offspring.
Also the BIGGEST FACT.... is regardless of how much or how less you believe in a God or the Afterlife once your life is in Danger, or you know you only have a matter of weeks or months to go, you will find a high % of even none religious people will start to find Faith, start to prey or try and believe in a God.
Because of the Fear of not Death..... but what happens after Death... If we knew for sure there was Life after Death, then the fear of death would not effect us.
It is the fear of death and what happens after death that greatly influences someone to turn to faith.
This is what has happened to Weyland, he is hopping that Shaw is right, because if she is then even if he can not be granted life... but if he finds out these beings are Divine like the Bible, then there would be Life after Death potentially for him...
But all he found was NOTHING!
But Shaw still holds Faith that their is SOMETHING!