The only intelligent thing to say about religion, God, heaven, etc. is "I don't know."
That's probably the best way to put it.
But, but, but, he's a genius.
If that is the only reason to believe whatever spills out of his mouth, then everyone would have to agree with whatever crap I decided to say. Technically, a genius is defined as someone with an IQ of 150 or higher and mine is 170. That doesn't mean that he or I have all the answers, because I sure as hell don't! Besides, IQ tests are not a true measure of intelligence and here's proof, one question that was on just one IQ test that I took years ago:
If all tics equal tocs, and all tocs equal tacs, do all tacs equal tics?
See what I mean...
If a scientist who spends their time essentially trying to learn everything they can about the world isn't allowed to pass judgement on what there might be in the world beyond what anyone knows... Then why are religious leaders allowed to go into detailed and elaborate specifics? That's a double standard.
Preachers, clergy, etc., do the same thing. They even do it more often, but it just doesn't get reported unless they build up a large following like those idiots, Al Sharpton, Jimmy Swaggart, and so on...,
- or - you have one that says something so totally outlandish like the world is going to end on May 21st.
As far as Carl Sagan and aliens. There's no hard evidence that aliens ever visited and realistically we are to primitive to worry about.
If I had just built a ship that could travel through time perhaps or at least cover vast stretches of space rapidly. I wouldn't bust my ass and burn my resources to get to Manhattan. Just to see a bunch of loud mouth bipeds using fossil fuels and killing each other.
I'd want to find like minded races that were on par with me or more advanced.
That doesn't negate absolutely any interest any aliens might have in Earth. Though the way I see it is like when humans find microbial life remnants on say Mars or proof that liquid water was there.
It's a great scientific find....and we likely never try to go back for more. In fact the biggest push for going to Mars at this point would be 1 just doing it and 2 colonization at some point. If there was bacteria there still alive...I honestly don't think that would spur us any faster to get people there or send any more landers than we already do.
Ask yourself this question; why have we advanced from stone tools to cell phones, computers, etc.? It can be summed up in one word, curiosity. Humans have an insatiable desire to learn. It is only reasonable to assume that if there is an alien species out there that has advanced to the point of interstellar travel, they too must also have the same desire to learn. Now, ask this, if the government announced that we had developed interstellar travel and discovered an alien species that was say, extremely primitive, do you think our scientists would want to go and study them? Obviously, yes, just as an alien species would want to study us.
Also, I don't think Mars would be an ideal planet to colonize as it's atmosphere cannot support human life. Even if we managed to terraform an atmosphere, the planet would still be useless as it's magnetic field is far too weak.