Hold on! We don’t know whether there’s any life in the rest of the universe, so let’s just stick with earth.
First question – do all life forms on earth feel pain?
To make the answer easier we can put all life into one of six kingdoms – bacteria, archaea (bacteria-like, but uniquely different), protists (very simple micro-organisms – diatoms, amoebae), fungi (from athlete’s foot to mushrooms), plants and animals.
The first five have no observed mechanisms for feeling pain, so we can say with some confidence that the vast majority of species don’t suffer. A planet with only these life forms would be a true Eden!
So what about animals? We’re different. We can’t make our own food from air, sunlight, salts and water like plants can, so we have to move around to gather energy to fuel our growth, reproduction, fight disease and so on. If we move into a dangerous situation it’s an advantage to be aware, so early on in evolution animals developed systems for recording pain – sense cells, nerves and brains. Muscles also evolved to help the animal escape. Tiny animals have simple systems and humans have very complex ones, but basically the idea is the same – they are essential for successful survival. These facts begin to answer the problem of pain – the ability to feel helps us survive in a world full of possible dangers. Some people are born unable to feel burning if they touch a hot oven and their lives are very difficult (congenital insensitivity). Sadly some people use our ability to feel pain to exert power over us, even to torture and murder.
But there’s a positive side.
Can a rose or a toadstool feel pleasure? They don’t have any mechanisms for feeling, so we must assume – no. But we animals can. Humans enjoy a vast array of pleasures from physical wellbeing, sex, family care to delight in the universe’s beauty, music, art, literature, architecture, scientific discoveries – the list is endless. And many people reduce pain and suffering by caring for those in need and bringing happiness to the sad and lonely.