When it comes to aliens, I'm with Michio Kaku. It is highly probable that we are not alone in this universe, however, we've seen how far we can go using fossil fuels, which are really the most primitive forms of energy available - we haven't really advanced beyond cavemen in that regard. The kind of space travel that can bring us close to another living world would require us to learn how to generate massive amounts of energy and learn how to traverse unimaginably long distances, which means we would have had to advance enough to really get a grip on the possibilities presented by physics. By the time a civilization can do that, they will have solved not only their energy problems, but also food scarcity problems (aliens will not come here looking for resources or food), and national, religious division would have become irrelevant.
If aliens are observing us, they think we are cavemen and are probably not interested.

A woman walked into a pub and asked the barman for a double entendre. So he gave it to her.