Now, I am a rather fervent "antitheist" in that I feel that religion is A Bad Thing, despite having been a religion major, studied various traditions in depth, and have taken numerous initiations into several traditions. Christopher Hitchens rather summed up my take on Established Religion in his quote: "Since it is obviously inconceivable that all religions can be right, the most reasonable conclusion is that they are all wrong." ... and the more insistent that a particular Religion is that they "are the one true path" the more likely I am to consider them dangerously deluded.
However, my strong agnosticism has an open window for "experiential" spiritual paths, ones where the individual "works on themselves" and are verifiable within one's own being (like the Buddha said: "Believe nothing ... unless it agrees with your own reason and your own common sense."). This is, no doubt, why I found Swami Prabhavananda's Religion In Practice so appealing, as it is not a doctrinal book, but a something of a guide for looking inside oneself (from a Vedanta perspective) and reaching out to the underlying spiritual realities.
This book, originally published in 1968, is a collection of talks that Prabhavananda gave at Vedanta Society locations in Southern California. There is a certain "going over the same points" in here due to this, as these talks were free-standing and not part of a course or curriculum. It has been assembled into five parts, "The Problem", "The Goal", "The Methods", "The Exemplars", and "Vital Questions on Religion Answered", each with various numbers of talks included. The most impressive part of this is "The Methods", which includes subject such as "Control of the Subconscious Mind", from which is this excerpt:
He then goes on to discuss a "fourth state" of consciousness called Turiya, which is one of those concepts that I had managed to not encounter previous to reading this book.... owning to our different states of consciousness, we find that it is quite impossible to reach freedom, to reach God. In our waking state of consciousness, with our physical senses, with our human minds which can only become conscious of objects and things, we cannot reach that pure consciousness, however we may try. Then we go to sleep, we dream. There again, in the sleep of dreams, we cannot realize that pure consciousness. Then we go into deep sleep, we become unconscious; but, there is still a veil of darkness covering our consciousness. We do not realize pure consciousness. So long as we live and move within these three states of consciousness, it is not possible to reach the realization of pure consciousness. We cannot see God, cannot realize God, within the provinces of these three states of consciousness that are known to us.
I recall that when I finished reading Religion In Practice, I was wanting to go buy copies for my friends and family (I was that enthusiastic about it), but found, at first glance, that it was out of print. Certainly this version (the 1969 second printing hardcover) was out of print, and this is the only thing that Amazon has listed. However, with some additional digging, I discovered that this is being offered by Vedanta Press on their web site in hardcover, new (I'm assuming), for the remarkably reasonable price of $8.95 ... which could explain why it's not out in Amazon or B&N (which take a very steep percentage, making it hard to sell low cover-priced books at anything other than a loss). While there are some copies floating around the used market, Vedanta Press may be your best bet on getting a hold of this. Needless to say, I'd recommend it to all and sundry!