There is, I have been told, a 1% difference in DNA between humans and Apes. Apes are, arguably, the most intelligent animals on the planet next to humans. I say arguably because hamsters are freaking brilliant Houdinis. Apes have been studied for their ability to use simple tools and can be taught to communicate through basic sign language. Their limitation is that they cannot see beyond themselves. They are not able to ask questions about the world around them because, as far as they are concerned, everything they observe is exactly what everybody else observes. Humans, up until the age of about 4, have the same limitation. It does not occur to them that someone else has a different perspective.
To demonstrate this, put a group of 3-4 year old children in a room and send one of them out into the hall so that they cannot see what is happening. With the one child gone, place 3 cups on a table and place a ball under the middle cup. Tell the children that you are going to invite the absent child back into the room but first you want the children to guess which cup the child will choose that holds the ball. They will all universally say the middle one because it would not occur to the children present that the child in the hallway would not know where the ball is. It does not occur to them that the one in the hall has a different perspective than their own.
This is the level of intelligence of an ape. Yes, they can learn simple modes of speech and how to use tools, but they will never be able to abstract beyond the ability of a 4 year old. They can learn dozens of words, but they cannot ask questions that would expand their knowledge. They will ask for a cup of water, but they are not able to ask why the cup is blue or why does water quench thirst. When our young children create their works of art, we proudly display them on our fridges. If we were to identify the smartest gorilla of them all and had them produce a work of art we would be amused and realize that, although it is impressive that the primate can learn to paint, we would just consider it cute and not close to the ability of our young children.
Now, imagine if another life form was 1% different from us in the same way we are 1% different from the gorilla. If they came down and took our brightest human, imagine what they would think. As Neil deGrasse Tyson surmises in various Youtube videos, their toddlers would have the same intellectual capacity of all the greatest human minds combined. The fridge faces in their homes would be filled with musical compositions and works of art that would surpass the greatest masterpieces ever created on earth. These same younglings would be able to perform advanced mathematics beyond anything accomplished by our scientists. Quantum physics experiments performed at our most advanced labs would be preschool activities in their world. Their forms of entertainment would be so beyond our ability to comprehend that no expert on earth could decipher what it was. Just imagine trying to explain the plot line of a science fiction novel to a child just learning to talk.
Now, consider what would happen if humans discovered a planet populated by primates. Would we bother to try to communicate with them? What would be the point? Most likely we would observe them from afar, but by and large we would do our best to leave them alone because we would not want to contaminate their biosphere. So why do we suppose that advanced civilizations that have the ability to travel across the galaxy would have any need to communicate with us?
What about God? What if God were 1% different than the life forms that are 1% more advanced than us? What if the laws that govern the universe require someone of that intellectual ability to be understood? If so, it may never be possible for humans in their current form to ever grasp the natural world. We simply are not evolved enough. We will require another 6,000,000 years of evolution before we reach that state. Perhaps speculating on the nature of God and heaven is like a toddler trying to understand marriage. When considering the afterlife, we have that same limited view as the ape. We just cannot see beyond our limited human perspective.
Will humans ever be able to travel the galaxy? Perhaps not at our current level of evolution but give it time. In the meantime, keep an eye on your pet hamsters.