It seems totally likely to me that there is life on other planets. Regardless of whether a person believes in God and Creation, or the Big Bang Theory; it still would not make any sense that of all the uncountable number of world out there, that this would be the only one to develop some kind of life forms.
I think that we have either been visited in the past by someone from another planet; or we had a very highly developed civilization in the far away past that escaped a ELE, and was able to send people back here to help humanity start over, in what is now our recorded history (last 6,000 years).
There are so many unexplainable structures right here on Earth that we are not capable of duplicating in this modern age , that it really seems likely that there was another form of life here that were more advanced at one time.
I would not be surprised if we didn't have some here already from another planet, and they either look like humans, or are like humans.