I dont. I just believe that God makes human a little better these days...
I believe there is a possibility that there is life of some kind on some other planet or planets, but I don't believe we've made contact of any sort and probably never will.
I believe they must be out there somewhere (the universe is unbelievably enormous, after all), but not necessarily that they've been here.
...crickets chirping in the background. Would I help if I told you that to err is human?