Our world, the entire universe, simply everything of which we are only a small but nevertheless important part of an incredibly large whole, certainly stems from one single source! From time immemorial we have been asking metaphysical questions, such as: How can there be a creative intelligence? Is there a God or whatever we want to call "him+her+it"? Is there a spirit, a "spiritual dimension"? And, of course, does our life end with death? Has an individual a free will? What is our "Self"? Was our universe really created by a Big Bang? These questions and many more will probably occupy all of our minds somehow at some time or other. Natural sciences and religions have often given us diverse, in many cases even mutually excluding arguments. Natural sciences and related fields currently still mainly adhere to notions which are reduced to materialism (naturalism). In these notions "God" or a "brain-independent spirit" have just as little place as our "Self" and an at least basic "free will", not to speak of a belief in a survival of death which is at best smiled at as "naïve romanticism". Based on a recent lecture, the author, physician and university professor once again suggests in this book, that such notions reduced solely to materialism are antiquated.