This claim makes no sense to me, but there's no point in posting one of the many definitions of "religion" and bulletpointing all of the ways science is separate from that definition. The mundane truth is that what, in common parlance, constitutes a "religion" is ambiguous. In actual fact, I find that people who make the claim in this thread's title tend to have a broad-to-the-point-of-meaningless definition of "religion" as "anything with explanatory force that anyone believes for any reason whatsoever." If this is the definition we're using, then fine, science is a "religion".
But it's still the only religion that requires its practitioners to back their claims with repeatable, falsifiable demonstrations of empirical evidence. And that's good enough for me.