What is a Mitre?
Mitres were historically worn by only by the high priest (sons of Aaron; Exo 29:9, Exo. 29:44, Exo. 30:30) as part of the holy garments commanded to be worn by God (Exo. 28:1-4, Exo. 39:27-28, Lev. 8:9). They were worn for both glory and beauty (Exo. 28:2).

Why Do We Wear Mitres?
The Book of Zechariah gives an account of Joshua the high priest (Ezr. 5:2, Hag. 1:1, Hag. 1:12, Hag. 2:4) standing before the Lord with filthy garments (Zech. 3:1-3). He is then cleansed by the Lord and given a change of rainment (Zech. 3:4). Part of the rainment that was given him was a fair (Clean; Tahawar, H2889) mitre (Zech. 3:5). This is symbolic of what happens in the spiritual realm when one is baptised. We first are presented before the Most High with filthy garments and therefore need to be cleansed (Isa. 1:16). After we are cleansed, we presented with clean and pure rainment (Isa. 1:18). As a representation of this in the physical, we therefore put on both white garments and white mitres.

Weren’t the Priests Only Allowed to Wear Mitres?
We take into consideration that the Most High promised to make us a royal priesthood (1Pet. 2:9, Exo. 19:5-6, Isa. 61:6). Through Christ’s sacrifice, the Most High will set up a nation of kings and priests after the order of Melchizedek (Rev. 1:5-6, Rev. 5:9-10).