Approximately one in ten people practices yoga in the USA today. They are not necessarily practicing regularly and often do a workout that is offered at their gym club or community center. It is simply an hour of exercise. No more, no less.
Many of the practitioners as they start to practice regularly notice some subtle changes in their psyche and physique. They are calmer, more resilient following times of stress and grief, and body muscles start to become lean and long. Many illnesses appear to disappear! Surprising qualities of intuition and synchrony start to happen. To many students of this art deeper questions of life and death, beginning and ending, and whereto/wherefrom start to arise, often based on suggestions from their instructors. It is a good thing.
Is Yoga a religion? Originally, yes. Many thousands of years ago. But what is religion? Hinduism, on which yoga is based, is not really a religion in the Western sense of the word. It is not an 'ism', since it is not theistic, therefore there is no identifiable one or many God/Gods. The thousands of 'Gods' in Hinduism simply try to make comprehensible to our little minds the awesome Energy that is 'Godness'. These are the thousands of qualities of Goodness/Godness that cannot be portrayed in one Being or non-Being. Hinduism is monistic, or everything/all is one/everything... I am the bird, I am the sea, I am the tree! I am everything, everything is me.
Does this conflict with your religion or lack of it? It shouldn't, and if you can step outside of any biases you may come to class with, you will see for yourself yoga's deep and powerful impact on your life and being. It is a secular practice, but on the other hand, it can enrich your own faith.
The other important aspect of yoga is discipline, but more on that next month. Meanwhile, be disciplined enough to schedule your classes for the entire month and show up without question.