A thief in the night comes SUDDENLY, not always invisibly.
But the kingdom of God does indeed come invisibly:
20 And being asked by the Pharisees, when the kingdom of God cometh, he answered them and said,
The kingdom of God cometh not with observation:
21 neither shall they say, Lo, here! or, There! for lo, the kingdom of God is within you.
22 And he said unto the disciples, The days will come, when
ye shall desire to see one of the days of the Son of man, and
ye shall not see it. Lu 17
You can't see it with the eye or touch it with the hand:
18 For
ye are not come unto a mount that might be touched, and that burned with fire, and unto blackness, and darkness, and tempest,
22 but
ye are come unto mount Zion, and unto the city of the living God,
the heavenly Jerusalem, and to innumerable hosts of angels, Heb 12
It is not of this world, Christ rules from the heavenly Jerusalem, now:
36 Jesus answered,
My kingdom is not of this world: if my kingdom were of this world, then would my servants fight, that I should not be delivered to the Jews: but now is
my kingdom not from hence. Jn 18