marxism is not a religion. envrionmentalism is not a religion. college is not a religion. consumerism is not a religion. social media is not a religion. football is not a religion. atheism is not a religion (but it is at least the only thing on this list that counts as a religious demographic). watching a lot of anime is not a religion. science is not a religion.
what is a religion? i don't know for sure. there probably has to be some connection to the supernatural, real or symbolic, for it to count. but i'm confident that the things i listed up above aren't religions, and i think most people agree with me even when they claim otherwise. how easy would it be for someone to get a draft deferral because twitter told them they should be a pacifist? how often will someone get a religious exemption from a law that clashes with the teachings of murray bookchin? how many interfaith groups are willing to try to bridge the sectarian divisions between man u and leeds?
the answers are between rarely and never. hell, atheists are still often excluded from interfaith stuff today and often sidelined or othered when included. and of course no one's going to actually invite the mickey mouse club to teach them about their cosmological or moral worldviews. these things are categorically considered to be not religion based on how we actually choose to interact with them. we may not able to be able to define the line between the religious and the secular, but most of us act pretty consistently about what is on one side or the other.
none of the aspects of religion people claim these supposedly religious things have actually seem to matter as to how they are understood and treated. history, ethics, cosmology, community, culture, hope, passion, all these things that we'd use to define human relationships to religion, don't actually cause us to look at those relationships as meaningful on the same level we are expected to look at someone's relationship to the faiths we're used to. our mouths and our hands are at odds, what we say is not what we seem to believe. why?
to be honest, i think this is just a rhetorical trick to try to make something look bad.
it may not be said out loud, but the implication of so many articles and discourses and arguments i've seen over the past decade is that in declaring something secular to be a religion, the audience of that declaration is meant to fill in the blank and understand it to be a false religion. not simply a pseudo-religion, but a true competitor for adherents. sometimes, especially when the audience is assumed to be christian, the hope is that the specter of mammon will creep through our heads and ward us away from this strange, profane thing. even when this isn't happening calling something secular 'a religion' takes away our ability to examine that thing on its own terms, and forces upon us a lens of critique not meant for examining anything but the sacred. it ultimately works to invalidate the many different ways in which we can see and touch and know and change the world, and unfairly reifies a very specific yet incredibly undefinable form of religion as the assumed default for everything that we do.
don't fall for this trick. there is more to this world and to you than religion, even if you yourself are religious. you are not making a mistake of cosmologial proportions simply by letting hope and passion take you, as long as you keep your mind open and thoughtful.