Let me preface this discussion with the disclaimer that I am not anti-religion. Religion is an Aristotelian attempt to codify a class of human experiences that are, in our present state, uncodifiable. The experiences, however, are valid, despite any embellishments that have, for a variety of reasons, been added. As an engineer, I must stand back and evaluate what is currently known and ascribe the rest to human invention.
What we know is that there is life after death. We know this because people have died and revived and told us about their experience. We know, from personal experience, that prayer works. We don't know why it works, and we don't know the details of our after lives. But, while there may indeed be an intelligence that designed and guides these systems, the question of origin does not concern us in our pursuit of knowledge specific to the structure of reality.
There is ample evidence of evolution in our own bodies, from the cold and fear-triggered goose bumps, designed to raise our fur on end, to the automatic toe clenching (to get a better grip on the limb) when we slip or loose our balance. There is also evidence in other animals, such as the vestigial leg bones in whales.
Then there's intelligent design. The theory of evolution underwent a significant evolution in the 1980s from Darwinism to intelligent design. The intelligence referred to is in the DNA, which automatically and proactively modifies itself to obviate any threat to the organism's existence. We see this in the fruit fly's evolution of a resistance to DDT and in staphylococci evolving a resistance to antibiotics, to name a few examples.
If you see another intelligence behind this mechanism, I cannot argue with you. But the fact is the mechanism exists, and it is the mechanism of evolution.
But the clincher to the argument for evolution is its major support system – the life cycle.
If a system is observed to be working, it must be assumed that it is working in accordance with a purpose. Working systems never occur randomly out of nothingness. They are always a response to a need. The question then must always be "To what is this system necessary?"
With that in mind, let's look at the system of the life cycle. All life has a beginning, springing from a seed. All life matures through a "childhood" into an "adulthood." And all life eventually ages and dies. To what is this system necessary?
In order to effect DNA modifications, they must be realized in another organism. Whales didn't suddenly change their legs to flippers to accommodate an aqueous environment. The evolution of flippers had to be accomplished by passing the modified DNA on to their progeny. Hence constant birth of new generations is necessary to evolution. And the old generations must die to make room for the new.
Why do we die? Because it is necessary to evolution.