So, people have called Atheism a religion, and now people call leftism a religion. Heh.
Religion is defined as "the belief in and worship of a superhuman controlling power, especially a personal God or gods". Now, some could argue that communist dictatorships are religions due to the deification of the dear leader, and that would be a valid observation, but this accusation isn't applicable to social justice. The aim is the emancipation of the individual to improve their material well-being in this world, and with that the abandonment of traditions which trap people within their hierarchy. Social justice is the opposite of a religion in that it's steeped in humanist values - the attachment of value to human rather than divine or supernatural matters.
You're appropriating a term to use as a snarl word, one which serves to create a false equivalence between one values system you don't like and a separate values system.
Is that the only definition of religion or is it your definition?
Its not even the only definition in the thread so far.