“Worthy are you to receive the scroll and break open its seals, for you were slain and with your Blood you purchased for God those from every tribe and tongue, people and nation. You made them a kingdom and priests for our God, and they will reign on earth.” (Rev 5:1-10)
https://bible.usccb.org/bible/readings/111722.cfm
A kingdom and priests for our God . . . the Second Vatican Council drew on this passage of scripture when speaking about the People of God: these faithful are by baptism made one body with Christ and are constituted among the People of God; they are in their own way made sharers in the priestly, prophetical, and kingly functions of Christ; and they carry out for their own part the mission of the whole Christian people in the Church and in the world.” Saint Elizabeth of Hungary (1207-1231) cared for the sick and is the patron saint of the Third Order of Saint Francis of Assisi. “Priestly people, Kingly people, holy people. God’s chosen people, sing praise to the Lord.”