Here is Martin Luther’s short exposition of the Lord’s Prayer, which I found in his Small Catechism. I have not included every question, but just the central ones. The bold is mine.
Our Father who art in heaven.
What does this mean? God would thereby [with this little introduction] tenderly urge us to believe that He is our true Father, and that we are His true children, so that we may ask Him confidently with all assurance, as dear children ask their dear father.
The First Petition: Hallowed be Thy name.
What does this mean? 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? 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.
The Second Petition: Thy kingdom come.
What does this mean? The kingdom of God comes indeed without our prayer, of itself; but we pray in this petition that it may come unto us also.
How is this done? When our heavenly Father gives us His Holy Spirit, so that by His grace we believe His holy Word and lead a godly life here in time and yonder in eternity.
The Third Petition: Thy will be done on earth as it is in heaven.
What does this mean? The good and gracious will of God is done indeed without our prayer; but we pray in this petition that it may be done among us also.
How is this done? When God breaks and hinders every evil counsel and will which would not let us hallow the name of God nor let His kingdom come, such as the will of the devil, the world, and our flesh; but strengthens and keeps us steadfast in His Word and in faith unto our end. This is His gracious and good will.
The Fourth Petition: Give us this day our daily bread.
What does this mean? God gives daily bread, even without our prayer, to all wicked men; but we pray in this petition that He would lead us to know it, and to receive our daily bread with thanksgiving.
What is meant by daily bread? Everything that belongs to the support and wants of the body, such as meat, drink, clothing, shoes, house, homestead, field, cattle, money, goods, a pious spouse, pious children, pious servants, pious and faithful magistrates good government, good weather, peace, health, discipline, honor, good friends, faithful neighbors, and the like.
The Fifth Petition: And forgive us our trespasses, as we forgive those who trespass against us.
What does this mean? We pray in this petition that our Father in heaven would not look upon our sins, nor deny such petitions on account of them; for we are worthy of none of the things for which we pray, neither have we deserved them; but that He would grant them all to us by grace; for we daily sin much, and indeed deserve nothing but punishment. So will we verily, on our part, also heartily forgive and also readily do good to those who sin against us.
The Sixth Petition: And lead us not into temptation.
What does this mean? God, indeed, tempts no one; but we pray in this petition that God would guard and keep us, so that the devil, the world, and our flesh may not deceive us, nor seduce us into misbelief, despair, and other great shame and vice; and though we be assailed by them, that still we may finally overcome and gain the victory.
The Seventh Petition: But deliver us from evil.
What does this mean? We pray in this petition, as in a summary, that our Father in heaven would deliver us from all manner of evil, of body and soul, property and honor, and at last, when our last hour shall come, grant us a blessed end, and graciously take us from this vale of tears to Himself into heaven.
What does this mean? That I should be certain that these petitions are acceptable to our Father in heaven and heard; for He Himself has commanded us so to pray, and has promised that He will hear us. Amen, Amen; that is, Yea, yea, it shall be so.