Are you planning on getting a visitor's visa for the religious conference and then attempting to convert it to a work permit?
No one can convert visitor visas to work permits. It doesn't happen. If you find an employer with an approved LMIA, you could apply for a work permit, but it takes 4-6 months for the LMIA to be approved, plus the processing time for the work permit, which could be months.
If your intention is to try to get a visitor visa for a religious conference and then get a work permit, you are not a genuine visitor and may be refused a visitor visa.