The wind bloweth where it listeth, and thou hearest the sound thereof, but canst not tell whence it cometh, and whither it goeth: so is every one that is born of the spirit."-- John 3:4-8.
[370]Seeing, then, that Jesus Christ is a glorious spirit being with a divine organism, and that as the wind cannot be seen, but comes and goes, so a spirit can thus come and go without being discerned by human eyes, could not our Lord be present and yet not observable by any natural eyes?
That is exactly according to the facts.

Satan is a spirit being.

For many centuries Satan has been the god or invisible ruler of the present evil world (2 Corinthians 4:3,4); yet no human eyes have seen Satan, although men have felt his influence and still feel it.
Satan is not only the god of this world, but he is the chief one of his wicked, invisible heaven; that is to say, the invisible ruling order of things composed of Satan and the other fallen angels who exercise power over human beings.

The apostle Peter said: "We, according to his promise, look for new heavens and a new earth, wherein dwelleth righteousness".

(2 Peter 3:13; Revelation 21:1-5) The coming kingdom of the Lord is the new heavenly kingdom.