Well, when you consider how immense the universe is, and how mamy incredible number of stars and planets there are, and we are talking in the trillions to septillions or more, I mean come on! There must be life out there.
Or planet was lucky enough to evolve life on it, but the chance of this happening is very very very slim, but when you take into consideration the number of planets in the universe no matter how slim the chances are, because there are so many planets, there is a chance for many planets to evolve life and intelligent life. Although this life may be so far away that it will be an extremely long time before a human being sees one.
Just look at the Drake Equation! That is just looking at the numbers in the Milky Way galaxy. Personally, I have no doubt that there is life and intelligent life on other planets, but obviously we will never get to meet other forms of intelligent life in our lifetimes. If we are lucky, what we may find in our lifetimes is bactercia on Mars or on Europa.