“‘And I heard another voice from heaven,….’ Either of another, or of the same angel, or rather of God, or Christ himself, since the persons addressed are called his people:

‘saying, come out of her, my people;’ meaning either his elect ones, till now uncalled, being such whom God had chosen for his people, and were so by virtue of the covenant of grace, were given to Christ as his people, and were redeemed by him, though, till this call, in an unconverted state; or else such who had been secretly called by the grace of God, but had not made a public profession of the Gospel, nor bore an open testimony against the Romish idolatry; for as the Lord had a righteous Lot in Sodom, and saints where Satan’s seat was, Rome Pagan, so he will have a people in Rome Papal, at the time when its destruction draws near; and these wilt be called out, not only in a spiritual sense, to quit the communion of the church, to forsake its idolatries, and not touch the unclean thing, separate themselves from her, and bear a testimony against her doctrines and worship, but in a literal sense, locally; they shall be bid to come out of her, as Lot was ordered to go out of Sodom before its burning, and the people of the Jews out of Babylon before the taking of it, Jeremiah 50:8 to which reference is here had: and as the Christians were called out of Jerusalem before the destruction of it: this shows the particular knowledge the Lord has of his people, be they where they will, and the gracious care he takes of them, that they perish not with others; and that it is his will they should be a separate people from the rest of the world; and this call of his sufficiently justifies the Protestants in their separation from the church of Rome, and every separation from any apostate church;

‘that ye be not partakers of her sins’: by conniving at them, or committing the same; and all such are partakers of them, and have fellowship with these unfruitful works of darkness, that are in the communion of that church; and those that dwell at Rome are in great danger of being so, and cannot well avoid it: yea, even those that only go to see it, and stay but for a time in it, and that not only through the strength and influence of example, but through the force of power and authority:

‘and that ye receive not of her plagues’; or punishments; the seven last plagues, which belong to her, the vials of which will be poured out upon one or other of the antichristian states, and the fifth particularly will fall upon Rome, the seat of the beast, and is what is here referred to.”

–John Gill’s Exposition of the Whole Bible