Perhaps the first thing we should do is sort out what secularism is as people have different ideas. I would propose that secularism isn't one choice amongst many beliefs nor that it is the mere absence of belief, but rather that it is the contested space in which other beliefs exist. As Smith puts it:
"A society is secular insofar as religious belief or belief in God is understood to be one option among others, and thus contestable (and contested)." -Id.
So secularism is not a religion, but it does create the opportunity for new religions or religious-like belief systems amidst all the doubt and contestability.
"It is the emergence of “the secular” in this sense that makes possible the emergence of an “exclusive humanism” — a radically new option in the marketplace of beliefs, a vision of life in which anything beyond the immanent is eclipsed. “For the first time in history a purely self-sufficient humanism came to be a widely available option. I mean by this a humanism accepting no final goals beyond human flourishing, nor any allegiance to anything else beyond this flourishing. Of no previous society was this true." - Id.