What Kingdom of God is spoken of in the second petition of the Lord's Prayer?
About the kingdom of grace, which, according to the apostle, is righteousness and peace and joy in the Holy Spirit (Rom. 14:17).
Hasn't this Kingdom come yet?
For some it has not yet come in full force, and for some it has not yet come at all, if sin still reigns in their mortal body, to obey it in its lusts (Rom. 6:12).
How does it come?
Secretly and internally.
The Kingdom of God will not come in a noticeable way... For behold, the Kingdom of God is within you (Luke 17:20-21).
Can't a Christian ask for anything else under the name of the Kingdom of God?
He can ask for the Kingdom of Glory, that is, the perfect bliss of believers.
I have a desire to be resolved and to be with Christ (Phil. 1:23).
About the third petition “Thy will be done as it is in heaven and on earth”
What does it mean to ask: Thy will be done?
This should ask God so that everything we do and what happens to us happens not as we wish, but as God pleases.
Why do you need to ask for this?
Because we often make mistakes in our desires, but God, infallibly, and without comparison, more than we ourselves, desires every good for us and is always ready to grant it, unless our self-will and stubbornness prevents it.
To Him who, by the power that works in us, is able to do exceeding abundantly above all that we ask or think, to Him be glory in the Church (Eph. 3:20-21).
Why do we ask for God’s will to be fulfilled on earth exactly as it is in heaven?
Because in heaven, holy Angels and blessed people, all without exception, always and in everything fulfill the will of God.