As all the subjects of the Kingdom of England are an integral in reference to the King and Laws, though they should for a time want inferiour Officers, and though they bee not in particular combinations, and so are destitute of the particular priviledges, and have no particular Officers to dispense God's Ordinances to them constantly, yet have they right by reason and Scripture rules to all the Ordinances of God, as well as baptism, and they covenant to submit to all God's Ordinances, even those of discipline, and are habitually under the habitual power of the Ministers office, and are capable of censures, as hath been shewed before: onely they want the opportunity of enjoying them constantly by particular Officers of their own. The right of an English man to the priviledges of the Laws, doth not arise by beeing actually under such and such particular officers in a corporation, &c. but by beeing members of the Kingdom. So is the right of visible beleevers to Church-priviledges, by being Christs visible subjects.
While I'm at it, here are a couple more quotations from Hudson on the same theme from his
Essence and Unity of the Church Catholic Visible (found in the Anthology of Presbyterian and Reformed Literature, vol. 5, ed. by Chris Coldwell [Dallas, TX: Naphtali Press, 1992]):
Yea, suppose a man should be a traveller [sic], merchant or factor [commissioned agent], and settled in no particular congregation, yet being a Christian he is a member of the catholic church. Yea and if he broach any errors, or live inordinately, he shall be accountable to the church wherein he for the present resides, or such crimes are committed, and he is liable to their censure, as being a member of the catholic church . . . Now prohibition is a censure. They are not to be left to the magistrate only, but to the church trial, for those crimes come not always under the cognizance of the civil magistrates, and if they do, he may be a heathen and will not regard an heretic, nor can judge of him. And if every kingdom will try murder, or treason, or any other soul crime committed in the same, though by a stranger, or alien, because the crimes are against their laws, and sovereign, though their laws pertain not to the country where the foreigner was born, and dwells, then much more shall every church try those members of the catholic church residing among them for their crimes, seeing they have all the same sovereign head, the same laws, and are all one body. (P. 35)
Yea, I conceive that there may be many belonging to the catholic church, that belong to no particular congregation, whose conversion has been by accidental occasion, as by reading, or discourse, or haply [perchance] hearing a disputation, or sermon, and yet their habitation, or imprisonment, slavery, banishment, travel, or other occasions may not suffer them to join themselves to any particular congregation, yet are visible Christians yielding professed subjection to the gospel in their lives and conversations. And are, by being of the catholic church, fit to be members of any congregation, but are actually none. . . . Suppose a man by transplanting into America, suffering shipwreck, should swim to some unknown land, and there living among the natives. Is that man without? Is he not [holy] hagios? Of what congregation was the Eunuch, that was baptized by Philip? And yet we doubt not to say, he was a Christian, and one of the church members; but it must be the catholic church. (P. 38)
Of course, we all have a duty, whenever possible, to be members of a particular congregation under the oversight of particular local elders, but it doesn't follow from this that those who cannot be in such a situation are not part of the visible church, for the visible church is not just particular but catholic. That's the point Hudson is getting at, and it is a great comfort to those of us who are in the sort of situation he describes (hopefully temporarily!).
For more, see here and here.