In my opinion, there is religion, and then there is spirituality. One is social, the other personal.
The biggest factor in how alike/different religions are is to look at the social organization and economy of the related culture. Hunter-gatherer, nature-oriented cultures, for example, almost invariably have animistic, earth-based religions that have shamans, a spiritual otherworld, frequently reincarnation with transmigration (humans can become non-human), and they see non-humans as persons with spirits (including animals, trees, places, etc.). With agriculture and chiefdoms and early states comes polytheistic religions with pantheons, and generally there are god/desses in charge of everything important to folks-fertility and the harvest, marriage and family, etc. Each of these trends makes lots of sense within the structure and organization of the societies in question. Monotheism only comes about with agricultural, state-based societies. As there is consolidation in political and economic power, there is a shift toward belief systems with consolidation of supernatural power (one God).
I do not think God judges us based on a subscription to a certain religion only, but rather based on our individual hearts. Religion is a social category; our spiritual life is what matters. I actually don’t think it’s so much of a literal judgment sending us to literal places (heaven or hell), but rather that both are states of being, and it is really up to us whether we cultivate our spirituality and hence enter the state of being with the Divine, or whether we do not and remain in the state of being without the Divine (in hell). In short, I think we get that which we’ve prepared our souls to receive. If we’ve prepared ourselves in spiritual matters, we receive communion with the Divine- and this might take different forms depending on what we have embraced. If we’ve prepared ourselves only for a physical, earthly existence, we will be unable to commune with the Divine, because we have chosen this world over the spiritual world.
Most of us will find one or another religion comforting, useful to guide us and give us fellowship, and helpful in our understanding of the Divine. Some of us will not find religion all that useful, and will forge our own way based on our spiritual experience, creating a religion of one.
We may not have one religion in common, but most people have a sense of the spiritual and a desire to commune with whatever, for them, lies behind that sense. learn as much as you can about religion and spirituality, and get in touch with your own spiritual side. if you find a religious tradition that speaks to you, that’s fine. if you don’t, that’s also fine. For me, I found it.
We each learn something different from the experience of being alive and asking questions. your journey is your own, cheesy as that may sound. No person has the same story or the same spiritual needs. Go with what feels meaningful to you.
The bottom line is this: Learn God’s qualities and try to replicate them.
The purpose of life is to try to understand the purpose of life. This makes a lot of sense to me. Try to find it out yourself. I found the answer in Islam.