Martin Luther -- Hallowed Be Your Name

As the head of the family should teach it in a simple way to his household.

What does this mean?

Answer:  God's name is indeed holy in itself; but we pray in this petition that it may become holy among us also.

How is this done?

Answer:  When the Word of God is taught in its truth and purity, and we as the children of God also lead holy lives in accordance with it. To this end help us, dear Father in heaven.

But he that teaches and lives otherwise than God's Word teaches profanes the name of God among us. From this preserve us, Heavenly Father.