A distinction must be made between religion and spirituality, because while religion poses some rather severe problems in the modern world, spirituality does not. The two are usually lumped together, thereby allowing generalizations about one to be applied to another. In fact, while religion and spirituality may often be found in close proximity with each other, each has certain features not necessary to the practice of the other. You can have religion without spirituality, and spirituality without religion.
Religion is primarily a system of beliefs concerning physical and metaphysical reality, delineating the sacred and the profane. These beliefs are transmitted orally or in writing; experience and practice are not essential components, and may be entirely absent in followers who nevertheless profess profound belief. Scripture and its interpretation by the clergy is the final arbiter. Correctness in religion can only be judged by comparison to external sources. Personal experience is highly suspect--due to its occult nature, it may even be delusional (religion's battle with the occult stems from the fact that it is itself a species of the occult.) The content, therefore, is cognitive and emotional, but only the cognitive content (belief) is approached in a systematic manner. It's main concern is to make truth claims about the world, even if the subject of those claims is hidden or shrouded in mystery. This is why religion may find itself in an adversarial relationship with science.
The sacred usually includes certain geographic locations, historical persons, texts, rituals, modes of dress, dietary habits, and the items used in these rituals. Although some of these may have had a practical purpose in the past (the avoidance of pork in desert religions is an example; pork spoiled quickly and dangerously in the desert heat), their continued persistence is traditional and fetishistic. This ritualistic behaviour seems eccentric or even foolish to those not of the faith. It is likely that it serves mostly to ensure a high level of commitment within the religious community and distinguish believers from non-believers. Seen in this light, the battles between various sects over minor details of conformity becomes understandable--these details exist precisely for the purpose of encouraging conformity.
There is usually an ethical system attached to the religion, but this ethical system is often simply an encouragement of adherance to the tenants of the faith: professions of faith may be granted more importance than ethical acts towards others. In a choice between adherance to articles of the faith and ethical behaviour towards others, faith may take higher priority. Ethical obligations usually follow tribal lines (towards fellow adherants.) In extreme cases, the ethical component may be dropped entirely, but this does not mean that belief system has been abandoned. Extremist sects merely alter the belief system, or may return to an earlier, more primitive version. Whatever else a religious fanatic may be, he is still slavishly devoted to his faith. Although touted as the most important aspect of the faith, the moral system is subject to intepretation, and is negotiable, and ultimately, dispensable.
Spirituality is primarily a system of practice and experience. Both cognitive and emotional elements are approached in a systematic manner. A system of beliefs may be present but the tradition can operate without them. There is no direct conflict between spirituality and science. The main goal is the attainment of happiness and well-being through an experience of communion with all of reality. The greatest obstacle to be overcome is our own obsession with self. The practice to attain this cannot be taught without considering relations with others, since the relatedness of self and other lies at the very heart of spirituality. Love and happiness require each other. An ethical system is therefore an integral part of the practice, and cannot be discarded without abandoning the practice entirely. If the ethical component is absent, claims to spirituality are a sham.
Rituals, when found in spiritual traditions, serve a practical purpose, and may be dropped if that purpose is not served, or if no purpose can be found for them. Texts may be studied, but only under the proviso that they are by nature flawed and incomplete--the spiritual experience cannot be put into words. Undue emphasis placed on any text or teaching is seen as an obstacle. The embodiment of the practice is the accomplished practitioner--but no teacher may become a target of worship and blind obedience. As Gautama Buddha said, "If you meet the buddha on the road, kill him!" External control is also an obstacle to enlightenment. Gurus and Messiahs maintain their flocks in a state of perpetual childhood. The very word flock is illustrative of the messianic attitude towards followers; they are sheep, to be herded, sheared, and slaughtered. The goal of spirituality is not to create followers, or to follow a leader, but to follow a path and help others who are willing to do the same. Proselytizing is considered somewhat vulgar and a symptom of arrogance.
The confusion between the two exists largely because many religious figures were in fact spiritual practitioners, who were later elevated to heroic or divine status in a religious pantheon. Many quotations from these figures make little sense in a religious context but perfect sense in a spiritual context. Spiritual traditions exist within religious traditions, but are kept quiet through constant censure. Mystics and monks of various religions will understand and agree with each other, but clerics and lay believers will fight tooth and nail. The truth is always and everywhere the same, but religion is obsessed with peripheral details, and the devil is in the details. Most religious believers are like sports fans who collect statistics and anecdotes, but have little idea what it is like to play the game.
The incorporation of spiritual figures into a religion is a matter of cooption and neutralization. Cooption prevents a schism from forming around the figure, and brings those who respect the spiritual figure into the fold. By elevating the spiritual figure to the level of hero or deity, the person in question is placed beyond the reach and emulation of the ordinary believer. His influence is limited to those sources controlled by the priesthood. One of the most blatant examples I found in a Catholic Bible, in a footnote for Jesus' words "Heaven is within you." At the bottom of the page was the explanation "ie., it is within your grasp, it is Jesus." The source of spirituality is externalized and removed to a distant pedestal, where the Church can charge admission. There is no greater embarrasment for a religion than a living prophet. A living prophet will contradict the clergy, and people will realize that he knows what he's talking about. Religion prefers its prophets dead, stuffed, and mounted as high as they can place them.
Religion is not spirituality. It is the dead husk of spirituality.