But, the wicked Northern Kingdom had broken covenant with God. There was no (except for Elijah and the 1000 that God had elected) semblance of any type of true gospel or worship of the true God there. The Northern Kingdom could not properly be called a church despite the existence of Elijah and the 1000.
This is the same with the RCC. The true believers that are there are despite the teaching of the RCC, not because of it.
By institution, I mean the official teaching of the church. The doctrinal statements and pronouncement that make them RCC. I do not mean individual people. This is why I say that a non-Christian organization (institution) cannot give Christian sacraments. The RCC is no more authorized to baptize and give communion than the local Rotary club.
According to God's inspired word, the remnant does make a valid assembly though Douglas. And in fact God's shows him 7000 not only 1000.
Romans 11:
1I say then, Hath God cast away his people? God forbid. For I also am an Israelite, of the seed of Abraham, of the tribe of Benjamin.
2God hath not cast away his people which he foreknew. Wot ye not what the scripture saith of Elias? how he maketh intercession to God against Israel saying,
3Lord, they have killed thy prophets, and digged down thine altars; and I am left alone, and they seek my life.
4But what saith the answer of God unto him? I have reserved to myself
seven thousand men, who have not bowed the knee to the image of Baal.
5Even so then at this present time also there is a remnant according to the election of grace.
Let us look at our Saviors own words addressed to the 'churches' in the book of revelation. He HIMSELF called them churches Douglas.
Pergemos held to the doctrine of Baalim and some nicolation stench
Thyatira: Notwithstanding I have a few things against thee, because thou sufferest that woman Jezebel, which calleth herself a prophetess, to teach and to seduce my servants to commit fornication, and to eat things sacrificed unto idols. And I gave her space to repent of her fornication, and she repented not.
Sardis: I know thy works, that thou hast a name that thou livest, and art dead. Be watchful, and strengthen the things which remain, that are ready to die; for I have not found thy works perfect before God. Remember therefore how thou hast received and heard, and hold fast and repent. If therefore thou shalt not watch, I will come on thee as a thief, and thou shalt not know what hour I will come upon thee. Thou hast a few names even in Sardis which have not defiled their garments, and they shall walk with me in white: for they are worthy.
Laodicia: I know thy works that thou art neither cold nor hot: I would that thou wert cold or hot. So then because thou art lukewarm, and neither cold nor hot, I will spue thee out of my mouth. Because thou sayest, I am rich, and increased with goods, and have need of nothing; and knowest not that thou art wretched, and miserable, and poor, and blind, and naked:
The Remnant: “And the dragon was wroth with the woman, and went to make war with the remnant of her seed, which keep the commandments of God, and have the testimony of Jesus Christ....Here is the patience of the saints: here are they that keep the commandments of God, and have the faith of Jesus.” Revelation 12:17, 14:12.
Therefore just as apostate Israel had a remnant of God's people serving Him, so does the rcc.