“Thy kingdom come. Thy will be done in earth, as it is in heaven.”
Matthew 6:10 — Greek Interlinear
Church Fathers on Matthew 6:10
It follows suitably, that after our adoption as sons, we should ask a kingdom which is due to sons.
This is not so said as though God did not now reign on earth, or had not reigned over it always. 'Come,' must therefore be taken for 'be manifested to men.' For none shall then be ignorant of His kingdom, when His Only-begotten not in understanding only, but in visible shape shall come to judge the quick and dead. This day of judgment the Lord teaches shall then come, when the Gospel shall have been preached to all nations; which thing pertains to the hallowing of God’s name.
Either it is a general prayer for the kingdom of the whole world that the reign of the Devil may cease; or for the kingdom in each of us that God may reign there, and that sin may not reign in our mortal body.