Supreme Court of Canada case law:
Syndicat Northcrest v. Amselem
This case proved that you DO NOT need to prove that you belong to an organized religion to claim that you are religious!
Read it here. You may choose to use this link when filing your religious exemption.
https://scc-csc.lexum.com/scc-csc/scc-csc/en/item/2161/index.do
46 To summarize up to this point, our Court’s past decisions and the basic principles underlying freedom of religion support the view that freedom of religion consists of the freedom to undertake practices and harbour beliefs, having a nexus with religion, in which an individual demonstrates he or she sincerely believes or is sincerely undertaking in order to connect with the divine or as a function of his or her spiritual faith, irrespective of whether a particular practice or belief is required by official religious dogma or is in conformity with the position of religious officials.