What is the priesthood of all believers?

The priesthood of all believers is, as the name suggests, the doctrine that all believers are priests. In the Old Testament, priests were hand chosen by God as mediators between Him and the people, and to offer sacrifices on their behalf. In the New Testament, by contrast, the only priest who mediates between man and God is the High Priest, the Lord Jesus Christ. As believers, we have direct access to God, as indicated by the tearing of the Temple veil upon Christ's death, and we are called to offer up "living sacrifices". Thus, rather than being an official role within the Church governance, "priest" is a title afforded to all believers.