It is written in the Bible in several places that God's desire is to create a people who are priests. "A nation of priests." Every single one of his children is a priest. We do not live in obedience to that.
A priest is a certain person who represents God, who connect God to, who serves other people in their relationship with God. There are certain tasks, certain areas of service, that complete these purposes o the priesthood. A priest needs to be trained in, and to practice these tasks.
Priests are an intermediary, a go-between, for god and people. So, a priest needs to be able and to practice praying for people. If the whole family of God comprises the whole priesthood of God, then all of God's children should practice praying for others.
If a function of the priesthood is to explain the character and nature of God, how to live his lifestyle, and how to improve the relationship between a person and God, then all of God's children should teach.
If a function of the priesthood is to perform a ceremony where a person declares his allegiance to God, that he now a part of God's family, and that he renounces his former way of living (not his physical family or people), then all of God's children should baptize.