I tend to think heaven is a state of unity with God, and hell is a state of separation from God. So regardless of my bodily form (or not), I am either closer to heaven or closer to hell. It is my hope that, where ever I go after this life, I journey ever nearer to God-- that God, Love, Christ is manifest ever more in me.
It took me a while before I grasped, through spiritual experience and not through intellect, the value of incarnation and of my own bodily experience. I became, at that point, overjoyed with life, so thankful to God for this amazing capacity to breathe- to experience the beauty that is life! When life seems exhausting to me, it is because I am not being aware of what it is to truly live. I am living in the world and not in God. When I'm living in the awareness of what is really happening, I just can't get enough of life, yet I am not afraid of death.
I'm reaching toward the kingdom of heaven within me. I don't want to wait until I die to get to heaven- I want to be in God right now.
I trust that God will put me where I should be after I die. Whether that is some brief rest in the Summerlands, or in a heaven like Christianity envisions, or in some new life (human or not, here or not), or whatever- it is not important. I have faith God will forgive me my mistakes and will help me journey onwards toward His/Her heart.
As for the oldest religion... The oldest form of religion is animism, found in nearly all indigenous, earth-based religions. The oldest religion that was highly structured and organized, and was heirarchical (with a priesthood) is, I believe, Hinduism. But state-based, centralized society with its large religion came very late in human history. We were hunter-gatherers living in small (10-30 people) groups for about 90% of human history. We figured out the whole agriculture and settling down thing rather late, and this is what allowed for an elite, specialized group of religious practitioners (priests) in Hinduism, Judaism, etc. Before that, we just had part-time guys and gals (shamans) that helps in mediating between our world and the world of spirit/otherworld.
Reincarnation is extremely common among earth-based, indigenous religions. However, many groups believed that we reincarnated with power animals (like ravens, killer whales, otters, etc.) back and forth over the years. Our brethren would die and become the animals that sacrificed themselves in the hunt for our survival, and later we would die and do the same for them. A never-ending cycle of mutual survival and care-taking with Nature. The main difference between this view and the views of reincarnation in modern world religions like Hinduism is that it seems with agriculture, people got uppity about their superior place in the food chain. So animals were seen as "lower" on the karmic ladder. The less free will and higher-order thinking, the farther away you were from reunion with the Divine (moksha). They also extended this to social caste and gender. So a woman had farther to go than a man, a lower class person had farther to go than an upper class person. This was all tied to perpetuating a caste based system that allowed the priestly class (Brahmins) to exploit the peoples they had conquered when they settled in India. It's really pretty fascinating history.
Suffice it to say that after agriculture, it seems in most religions animals and the rest of nature began to be regarded as "less than" humans in a spiritual sense.
I'm not sure that is the right way to look at animals and what we can learn from them...
And wil- that is very insightful about our bodies. Even in this life, our physical form is a transitory, ephemeral thing. It is only an illusion that we have any sense of bodily permanency. Kind of mind-blowing when you really think about it.
