There is overwhelming scientific evidence for the fact that the functioning of the brain produces consciousness. When the brain does not function in the right way, it no longer produces consciousness. When it functions differently enough, it produce a different consciousness. There is no scientific proof of the concept of a soul existing beyond people's conscious imagination and desire. There is no scientific proof that consciousness exists beyond the functioning of the brain as a separate entity as proposed by dualist thinkers.
We know that the brain is very complex with tens of billions of neurons each connected to each other in sometimes thousand of points called synapses.  Thus we know that the brain can functioning in an innumerable amount of different ways. This potential complexity of structure and functioning correspond to numerous potential and actual versions of consciousness. These many different ways functioning can be linked together to produce different sequences of different consciousnesses or awarepaths. Awarepaths correspond to what we call peoples lives.
People do not want to give up on believing in or proving the existence of a soul or a separate mind dualism because they believe that concepts like that are needed to allow for life after death and immortality. The science of psychexistology shows that a soul is not necessary for life after death or immortally.