False. It is spoken to everyone, all you have to do is read the next two verses to see that.
Rev 3:20 Behold, I stand at the door, and knock: if any man hear my voice, and open the door, I will come in to him, and will sup with him, and he with me.
21 To him that overcometh will I grant to sit with me in my throne, even as I also overcame, and am set down with my Father in his throne.
22 He that hath an ear, let him hear what the Spirit saith unto the churches.
Yes, Jesus is speaking to the churches, but he is also speaking to everyone else. If you have ears on the side of your head, then Jesus was speaking to you also. And this is just a figure of speech, it is also intended for those without ears. If a person were born without ears but could read the scriptures it is intended for them also.
When you receive Christ you are born again. You cannot become unborn once you are born, and being born of God you cannot die.
One should be careful in taking this verse too far in either direction.
"Any" is a funny word. It can expand and contract based on the context. To base ones take on this verse on the phrase "any man" would be, at best, problematic. Notice, for instance, several cases where "any man" is used but where limiting it to mean "any man of this particular group being addressed" makes a lot more sense than "absolutely any man whatsoever":
Exo 24:14And he said unto the elders, Tarry ye here for us, until we come again unto you: and, behold, Aaron and Hur are with you: if any man have any matters to do, let him come unto them.
"Any man" includes gentiles or even the past dead or yet to be born? Or "any man" includes merely those Israelites gathered there?
Leviticus 1:2
Speak unto the children of Israel, and say unto them, If any man of you bring an offering unto the LORD, ye shall bring your offering of the cattle, even of the herd, and of the flock.
"Any man" includes gentiles as well? Or "any man" is just referring to any man who is a Jew (or proselyte even)?
Leviticus 15:2
Speak unto the children of Israel, and say unto them, When any man hath a running issue out of his flesh, because of his issue he is unclean.
Ditto.
Leviticus 27:9
And if it be a beast, whereof men bring an offering unto the LORD, all that any man giveth of such unto the LORD shall be holy.
Ditto and etc. etc. etc.
So, arguing that "any man" must necessarily mean all men universally is fallacious. Any man legitimately restricts itself to the group that is being addressed - in fact, such should, if anything, be the default assumption. Thus, for this verse to be seen as necessarily addressing all men universally (vs. "any man" within the particular context of the church) it would need to be shown that Christ is addressing all men everywhere.
However, doing that is problematic at best. First of all, the passage specifically identifies the audience as being the churches. No where does the passage say that the audience is universally meant. Is it possible to demonstrate that there is a universal element meant in this passage? Possibly. However, Winman's attempt to do so relies on a fallacy of begging the question. He first assumes that since such phrases such as "any man" and "He that hath an ear" *can* be meant universally they therefore *must* be meant universally (and thus the passage is addressing everyone). Such is not the case though. These sorts of phrases *can* be meant universally, true enough, but it is just as likely (if not more) that they are restricted to the particular audience they are being addressed to.
So, the presence of such phrases cannot legitimately be used as proof they are meant universally since is just as legitimate to see them as restricted to the audience being addressed. (begging the question).
At the same time however, even if we concede that the primary audience is the church it would be just as fallacious to insist on the "fellowship" vs. "relationship" sort of dichotomy. For one such an insistence is illogical. Christ is speaking to the churches yes, but to insist on "fellowship" only is in view in this passage would require that one assumes that every member of the church actually is a believer and has fellowship. The passage is addressing the church (mixed with believers and unbelievers) and not specifically the saints or elect (believers only). Thus, for this first reason, it would be taking the passage too far to insist that fellowship only is in view - logically relationship could be included as well in the passage even if "any man" is restricted to those in the church.
Secondly, even if the church is the primary audience and "fellowship" is the primary point to be taken from the verse. It would be fallacious to insist that this is the *only* application we could take from this passage. After all, theologians (Cists among them) regularly take principles found in one passage and use them to interpret another passage w/o restricting it to its primary meaning or audience. As long as one is careful to distinguish between what the verse is actually saying or who its primarily addressing and what one can logically infer from the passage, its not a problem.
In short, neither side can take this one passage and use it to argue pro or contra Cism.