I'm not convinced that's true. Nor am I convinced that all religions are focused on whatever afterlife concept they might have. The ancient Greeks often seem to have imagined the afterlife as dull, grey and dreary. The Confucians don't seem to have emphasized it. Ancient religions were often focused on acquiring divine favor in this life, plentiful harvests, healthy babies and so on. The Buddhists emphasize escaping from the endless wheel of rebirth. Some concepts of an afterlife involve bodily resurrection. The Buddhists explicitly deny the existence of a soul. Even if that is arguably a common denominator of all religions (which I doubt), it still doesn't define what religion is. In point of fact, I don't think that anyone has ever produced a truly satisfactory definition of religion. It's still an open question in academic religious studies. What we have instead of a dictionary-style definition is something more descriptive: a whole collection of qualities that religions often exhibit. Religions are recognized as being religions by family resemblance basically, by their possession of a sufficient number of these qualities. (Nobody has ever determined what counts as 'sufficient' either.) But having said that, it's quite possible (even probable) that there's no single quality that all religions possess in common that somehow qualifies them as religions. I think that just about all religions involve personal and social practices. But religious practices needn't be focused on afterdeath experience. They can be focused on improving one's fortunes in the here and now. They can be focused on maintaining the order of nature. They can be focused on maintaining ideal social relationships between people. And they can be focused on psychological suffering and the end of suffering. Maybe, if we adopt a very narrow view of what religion is.