There are no unanimous beliefs about afterlife in satanism. Everyone has his/her own opinion, here is mine.
Yes, life after death exists. Moreover, there is no real death, because you exist in spiritual plane and physical one at the same time. You may end your physical part but you still exist and can project yourself into another body – reincarnation. To be exact, on that level time is irrelevant and all happens now, so all other lifes happen at once. More of your incarnations may exists in the same time and space. Your higher self is a group consciousness that creates temporal personalities that adds to the whole. It doesn’t limit itself to human lifes, it projects itself on animals, plants and more at the same time. Often animals at home are part of your higher group consciousness. There are various levels of consciousness and in each life new ego, new personality is created, yet the real you is the you behind it.
Have you ever dreamed about being a different person, having a different gender, different life, different character yet you felt this is you as well? I have. In similar way, although all lifes have different personalities, they are still you in a wider sense.
So what happens exactly after death, what one feels? – you may ask. Answer is simple and complex at the same time, because all levels of consciousness exist at the same time in physical life and after “death”. But one thing at a time.
As an ego, you experience contrast thanks to physicality. This contrast allows you to shift your vibrations in different direction then your higher self (it creates negative emotions). No matter your state in a moment of death, you loose your temporal construct and synchronize with your group consciousness, leaving all negativity behind, meaning that death is always an enjoyable experience.
As said above many times ;), all planes exists at ones, so from one side your consciousness emerges to a group consciousness, on other hand, character as you were, exists separately in much better form in some dimension and can follow with his/her life, developing interested but without physical limitations. This also adds to the greater group mind. This is also the plane you contact with when speaking with death.
Conscious energy transcendences time, so there is no end of incarnations from that perspective. Source consciousness projects itself, growing, developing. To be more clear, a group consciousness isn’t the universe, the all or the whole. It’s still individualistic, so my higher group mind may be very different from yours.
How do I know that? Hard to explain. It comes after all experiences and knowledge in my life and I am still improving my views on that topic. I always believed in reincarnation, or to be exact, I was aware of it since always.
As a small kid, about 3 years old, I knew I existed before. Not in a womb, but as a mature person, many times even. I was just frustrated I couldn’t access those memories. But the certainty, that inner knowledge about being alive before was always part of me. This is something I can’t prove or pass. It’s how I feel. It’s part of my mind continuum. The older I am, the more things emerge and pieces fall in the place.