Religion ordinarily involves all of the following: first, a system of beliefs or statement of doctrine concerning so-called "ultimate reality"; secondly, an associated moral or ethical code of conduct; thirdly, participation in prescribed forms of ritual, observances and other acts of devotion.
In addition, religion ordinarily involves both “faith” and “worship”, accompanied by a system of moral philosophy or particular doctrines of faith as well as a religious community which supports that faith and its organization and practices.
Mindfulness is simply the practice of the presence of the awareness of the action of the present moment ... that is, the practice of paying attention, in the present, purposefully and receptively, choicelessly and non-judgmentally, to whatever arises in the present moment ... moment to moment … both inside and outside of us.
Forget about "expanded consciousness", so-called higher orders or levels of reality, and all notions of transcendence. Meditation may well bring us to a state of choiceless awareness and detached, but otherwise bare, attention that some describe as being "supramundane", "transnatural" or "transrational", but true meditation is grounded firmly in everyday reality, that is, in the one order or level of reality in which we all live and move and have our being.
Mindfulness is not a religion, or even a philosophy, but rather a way of being, a way of life, a journey in self-discovery, and an education. Mindfulness, being devoid of all notions of religiosity, is entirely experiential and, unlike most if not all religions, it is empirically based.