There are two separate realms, the earth and the heaven. They have different qualities, and different purposes. God reigns in heaven, and is the ultimate authority. In heaven there is no question but that all is according to the word of God. On this earth, however, agency reigns in all of its glorious promise and wonderful confusion. God’s word may be the rule of heaven, but on earth it is not so clearly dominant. Nevertheless, our agency does allow us to accept that word and implement it in our lives. Thus part of our prayer is that the heavenly become part of our earthly experience. We pray to bring heaven into this earth, and into our hearts.
Textual: The 3 Nephi redaction removes the entire first phrase from the Matthean text:
Matthew 6:10
10 (Thy kingdom come.) Thy will be done in earth, as it is in heaven.
This is an unusual deletion. It is quite certain that this was part of the Old World version of the prayer. It is attested in the various manuscripts of the text, and corroborated in the Didache, a very early second-century church manual:
“Do not pray like the hypocrites, but rather as the Lord commanded in His Gospel, like this:
Our Father who art in heaven, hallowed be Thy name. Thy kingdom come. Thy will be done on earth, as it is in heaven. Give us today our daily (needful) bread, and forgive us our debt as we also forgive our debtors. And bring us not into temptation, but deliver us from the evil one (or, evil); for Thine is the power and the glory for ever.” (Italics added. Didache).
The removal of the phrase from the Book of Mormon has not altered the way in which the verse is seen by modern LDS authorities. For instance, it is assumed to be part of the phrase when President Anthony W. Ivins concludes his conference discourse:
“May the blessings of the Lord be upon you. May his protecting hand be over you, and the guidance of the Holy Spirit direct you and abide with you and all who seek to establish righteousness and justice upon the earth; that God’s kingdom may be established and his will be done on earth as it is in heaven. This is my humble prayer, my brethren and sisters, in your behalf and in behalf of all the world Amen.” (Italics added. President Anthony W. Ivins, Conference Report, April 1930, First Day—Morning Meeting 19 - 20.)
The deletion is more unusual in that the retained phrase flows from the deleted invocation of the presence of God’s kingdom on earth. The reason that God’s word would be done on earth as in heaven is that the kingdom of God would be on the earth. Thus the Old World context of this line in the prayer is dependent upon the conception of the coming of the kingdom of God.
In what context is this phrase inapplicable in the New World? It is possible that the removal of this phrase has to do with the Messianic associations of the invocation that the kingdom of God come. In the New World there is a dual association with the Messiah. There is the Atoning Messiah and the Triumphant Messiah. While the kingdom is associated with the Triumphant Messiah, the presence of the Atoning Messiah in their midst might indicated that at least some portion of the kingdom had come. The presence of the Savior in their midst is the presence of that kingdom, and therefore perhaps redundant that they pray for its coming.
The second reason for the removal of the phrase has to do with the differing contexts of the Old and New World. In the Old World the political domination of Israel by a foreign nation was the harsh reality of everyday life, and the constant expectation of Israel was that their Triumphant Messiah would come to redeem them physically. In the Old World, the prayer continues to recognize the coming of the Messiah, but continues to push that ultimate political solution into the future. The Book of Mormon context has no such political domination by an outside force, therefore no such constant desire for the advent of the Triumphant Messiah. For the Book of Mormon the emphasis was clearly on the coming of the Atoning Messiah, and it was he who stood before them to give them the instruction on prayer. Therefore, the emphasis on the continual patience for the awaited kingdom was unnecessary.