I think I came across this quote in a book called The Borderland of Right and Wrong by Theodore Graebner. I found it quite well said. Given what Pieper says here concerning things not addressed in Holy Scripture, must we then allow them (I’m thinking primarily of worship practices here):
An orthodox church body must hold fast to the entire Word of God and to all the teachings revealed in it. To dispense from the acceptance of this or that Scriptural doctrine is an offense against the majesty of God. But the converse is also true. In order to claim the orthodox name, a church body must permit all those things to be free which are not commanded in God’s Word. It must not prescribe to any of its members to believe or to do aught that God has not in His Word prescribed to men. When a religious body does not strictly draw the line of distinction between things commanded and things left to our freedom, that church body likewise sins against the majesty of God by placing itself in the stead of God. God has reserved to Himself the right to command to Christians anything that is to be binding on conscience. ‘One is your master, Christ.’ A church body which restricts evangelical liberty by laws of its own misleads the people into idolatry; for inasmuch as a Christian in ecclesiastical, spiritual matters accepts any command from men, he apostatizes from God. Such a church commits grand larceny on her members, who have all received Christian liberty from their Lord, freedom from human commandments. Indeed, a church body of that kind would subvert the entire order which was to be characteristic of the church, by making a kingdom of this world out of the Christian Church. The kingdoms of this world have the right to issue laws which transcend God’s Word (if not in contradiction to it). But the church has no such right, has no power to legislate beyond the Word of God. It can command only where God has commanded in His Word.
You intend to become Evangelical Lutheran preachers. I charge you therefore to adhere to the principles of our dear church also in this matter – under no conditions to allow liberty where Scripture commands and, on the other hand, never to command anything where Scripture is silent. Only so you will become faithful servants of God and of the Lutheran Church.