“Thy kingdom come.” This concerns something to be achieved, something not yet here. The kingdom of God means the complete filling of the entire soul of intelligent creatures with the Holy Spirit. The Spirit bloweth where he listeth? We can only invite him. We must not even try to invite him in a definite and special way to visit us or anyone else in particular, or even everybody in general; we must just invite him purely and simply, so that our thought of him is an invitation, a longing cry. It is as when one is in extreme thirst, ill with thirst; then one no longer thinks of the act of drinking in relation to oneself, nor even of the act of drinking in a general way. One merely thinks of water, actual water itself, but the image of water is like a cry from our whole being.
Source: Waiting for God