We are not alone in the universe. Of that we can be sure. But our companions are not little green men with telepathic powers. Reality is not in alien spaceships and highly advanced civilizations on far off planets. Reality, our reality, is something much closer to home.
The Bible is full of supernatural events and visitors. Angels, demons, beings in heaven of all different sorts. Read through revelation and you quickly see that God is a God of variety. Just as there are millions of different forms of life on earth, heaven is filled with that same variety.
Our companions in the universe are spiritual beings, created before this particular universe was created. They are not bound by the physical laws of our universe. What laws they are bound with we may not know for sure, but we can be sure they are not exactly like us.
These beings, can be divided into at least two general sets... Good and bad. Those that serve God and those that rebelled against him. Both sets are roaming the universe and earth. They occasionally interact with man on various levels.
This is separate from the souls and spirits of people who have died. Whether those are also roaming is yet another debate not easily resolved.
So rest assured that we are not alone, the air is filled with beings, some for us, some against us. Sometimes they influence, sometimes control, sometimes watch. We are never alone.
Also rest assured we are safe. Man was given dominion over the earth. We are in control here. Man was further given dominion over the spirit world through Jesus name. We can walk in his service and thereby be his proxy exercising his authority over all. No reason for fear in our hearts. No created being is greater than Jesus, and we carry his authority in legitimately using his name.
So no aliens. Not in the Hollywood sense. But we are not alone.