From a Satanic perspective, belief may not be the right word. The after life is something we assume does not exist because it hasn't been proven and we really don't waste our time trying to figure out if it does.
By shunning such mystical predictions, we devote all our energy and motivation into enjoy THIS life here and now.
One tends to find in the spiritual religions that people are so hung up about what's to come after death, that they convert life into one long waiting room session. They live in fear that they will be judged by this big guy in the sky and directed to doom or bliss.
To answer your last couple of questions, science has clearly told us how one is born/created.
What happens after our life? Most will never know because they will be dead, hence our fulfillmnent of life now.
Lucky for me, I will be around for a long long time, so it is a pointless question for me to answer