Your kingdom come, your will be done,
on earth as it is in heaven.

Matthew 6:10

When we pray ‘Your kingdom come’, we are praying that the devil’s kingdom will be demolished in the world. His kingdom stands in opposition to Christ’s kingdom. Satan has his kingdom by conquest; he conquered mankind in paradise, and now he sets up his throne in the hearts of men (Eph. 1:1-2). Most kingdoms in the world pay tribute to him, and they are kingdoms of impiety and slavery. Nothing but sin goes on in his kingdom: murder, heresy, lust, treachery, opposition and division are the constant trade in his dominions. He is an unclean spirit and his subjects are held captive under his grim tyranny. Other tyrants rule over the body, but Satan’s kingdom rules over the soul. He rides men as we do horses. Other tyrants have some pity on their slaves. Though they make them work in the galleys, they give them meat and their hours of rest. Satan is a merciless tyrant; he gives his slaves poison instead of meat, and dirty lusts to feed on. He gives no rest but hires them out to do his drudgery. When he entered Judas, he sent him to the high priests, from there to the garden, and never let him rest until he had betrayed Christ and hung himself. When men have served him to their utmost strength, he welcomes them to hell with fire and brimstone. Let us pray that Satan’s kingdom may be overthrown. It is sad to think that men are willing slaves to Satan. They will fight and die for him, therefore he is not only called ‘the ruler of this world’, but ‘the god of this world’ (John 12:31; 2 Cor. 4:4). This shows his power over the souls of men. O let us pray that God would break the scepter of his kingdom, that Michael may destroy the dragon, and that the hellish kingdom of darkness may be beaten down! His kingdom must be thrown down before Christ’s kingdom can flourish in its power and majesty.

Thomas Watson, The Lord's Prayer, pp. 61-62