The Priesthood of All Believers in Luther on Worship

Luther on Worship is a fantastic little book. 

One of his gems is regarding the relationship between the Priesthood of all Believers and the Office of the Holy Ministry. In the WELS these are conflated - there is a priesthood of all believers, there are ministerial functions (as opposed to an office), and anyone in the priesthood can perform those functions subject to the headship principle. 

The author provides an excellent insight that challenges that view. Starting in the chapter on "Faith and Worship"

As fellowship between the "God-for-us" and man, faith constitutes the highest form of worship (WA 40, 360) 

He goes on to discuss faith's dependence on Word and Sacrament

Faith dare not be isolated from God's redemptive action in Word and sacraments as it reaches us through the office of the ministry.

Finally,

Man becomes a "priest" "passively", as it were, by receiving Christ's work through Word and Sacrament. 

 He justifies this view in the following chapter "The priestly sacrifice of believers"

All who receive the Lord by faith are priests of the New Covenant. Here is the foundation for the priesthood of all believers (WA 8, 415; 8, 422; 12, 179). As Christ is a priest, so is every Christian who clings to him in faith. ... as he is the Son, the Heir, and the true High Priest, so the believers are sons of God, heirs, and priests. (WA 7, 56)

 Luther based the priesthood of all believers on the "royal priesthood" of 1 Peter 2:9 and on Revelation 1:6, 5:10, and 20:6 ("priests of God and of Christ"). To "be a priest" equals in biblical language to "believe in Christ" and to "be a Christian." The title "priest" is common to all Christians.... 

The Holy Spirit in the New Testament carefully avoids applying the name of priest (Sacerdos or Pfaffe) to any of the apostles or any other office. It is solely the name of the baptized or Christians.  (WA 38, 230. Cf 7, 57f; 8, 253, 416; 12, 178; 6, 408, 564; 38, 229)

The New Testament priesthood is in the personal dimension. It is not an office. In the form of an office, the Christian church has ministers, but no priests. A priesthood implies sacrifices... What is the sacrifice that is related to faith? Luther points to the sacrifice of praise and thanksgiving, of prayer, of the body. 

Indeed, the word ἱεράτευμα (priesthood) appears only in 1 Peter 2:5 and 2:9. The more generic ιερος (preist) in the Gospels refers exclusively to the Levitial priests, in Acts there is an additional reference to priests of Zeus. The word does not appear anywhere else except in Hebrews and Revelations. In Hebrews the references are almost exclusively to the discussion on Melchizedek in chapters 7-9 with two references in Hebrews 11 to the levitical priesthood and then to Christ. The three references in Relvelations as previously discussed are part of the priesthood of all believers. This quick word study confirms the thesis that the priesthood of all believers is a separate entity entirely from the office of the holy ministry.

I highly recommend the book in its entirety.