What is the "house" in Hebrews 3:6?

But Christ as a son over his own house; whose house are we, if we hold fast the confidence and the rejoicing of the hope firm unto the end.
Heb 3:6 (KJV)

The Church is metaphorically regarded at Christ's building, thus "whose house are we". This ties in with this passage in Ephesians 2: 19 Now therefore ye are no more strangers and foreigners, but fellowcitizens with the saints, and of the household of God; 20 And are built upon the foundation of the apostles and prophets, Jesus Christ himself being the chief corner stone; 21 In whom all the building fitly framed together groweth unto an holy temple in the Lord:
22 In whom ye also are builded together for an habitation of God through the Spirit.

The Church (every believer) is also called "the temple of the Holy Ghost".

Ephesians 2:19-22

The Church on the last day

The Bible says Christ lives inside of believers like we’re his home

“Now therefore ye are no more strangers and foreigners, but fellowcitizens with the saints, and of the household of God; and are built upon the foundation of the apostles and prophets, Jesus Christ himself being the chief corner stone;

in whom all the building fitly framed together groweth unto an holy temple in the Lord: in whom ye also are builded together for an habitation of God through the Spirit.”
‭‭Ephesians‬ ‭2:19-22‬ ‭KJV‬

“ we are his house “ means his spirit is dwelling in us . In the Old Testament the temple was the dwelling place the habitation but in the New Testament we are his habitation where his spirit dwells

“What? know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own? For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God's.”
‭‭1 Corinthians‬ ‭6:19-20‬ ‭KJV‬‬

“House” here is best understood as “family” but with a royal connotation. Like “the house of Windsor” is a multi-generational royal family. Spain has the house of Castile, etc. While the familial bond cannot be denied the authority that resides within the family name is paramount.

The idea of the spirit of the king living “in” someone was not new. It was understood that the grace of kings extended into his whole family. When a member acted within the spirit and grace of the king then he/she would rightfully be attended by the king’s authority. The king may also delegate grants of his authority to any member he wishes. Again, as the person operates within that grant, he/she is regarded as the king himself.

This scripture answers the question which the saints are the house.

The saints are like a building where the saints are built upon each other.

Which Jesus is the chief cornerstone of the building, and then Peter is the next person built on Christ and then the disciples and the order that people are saved.

Amen.

There's also this:

1Peter 2:2
As newborn babes, desire the sincere milk of the word, that ye may grow thereby:

1Peter 2:3
If so be ye have tasted that the Lord is gracious.

1Peter 2:4
To whom coming, as unto a living stone, disallowed indeed of men, but chosen of God, and precious,

1Peter 2:5
Ye also, as lively stones, are built up a spiritual house, an holy priesthood, to offer up spiritual sacrifices, acceptable to God by Jesus Christ.

.
Jesus' house is the Father's house too because they're related; and consists
of servants along with the regular family. For example, Moses was a member
of the service staff. Jesus outranks all of them because he's the Father's
principal heir whereas the servants are entitled to nothing.

Moses is sort of like Downton Abbey's butler Mr. Carson, and Jesus is sort
of like Grantham's heir Mathew.

Now the difference between Moses and Christians is that Christians are
God's heirs the same as Jesus (Rom 8:17) which of course makes Christians
superior to Moses.

* If perchance a Christian should encounter Moses. It would be a very
good idea to treat that man with the respect he deserves. Christians owe
their position in God's house to grace, whereas Moses fully deserves his
position. Let's not be forgetting that.
_

It's a bit like verse 14 of the same chapter.

Hebrews 3:14
14We have come to share in Christ, if indeed we hold our original conviction firmly to the very end.

The chapter is saying that we must continue to be faithful like all of the other examples of faithful people before us. If we don't then the consequence is not sharing in Christ.

Salvation.


Hebrews 3:1-6
Therefore, holy brethren, partakers of the heavenly calling, consider the Apostle and High Priest of our confession, Christ Jesus, who was faithful to Him who appointed Him, as Moses also [was faithful] in all His house. For this One has been counted worthy of more glory than Moses, inasmuch as He who built the house has more honor than the house. For every house is built by someone, but He who built all things [is] God. And Moses indeed [was] faithful in all His house as a servant, for a testimony of those things which would be spoken [afterward,] but Christ as a Son over His own house, whose house we are if we hold fast the confidence and the rejoicing of the hope firm to the end.


Note that here Christ is being compared to Moses, and shown to be far greater. It is written, every house is built by someone, but He who built all is God.
Moses built a house, and was a servant in it - that house is the covenant of the law. As a servant Moses built that house for his Master, so that he might serve in it.
Christ however is not a servant but a Son over His own house: He did not build it as a servant but as He who would own it and rule over it.
He is contrasted with Moses here: He is not one who has merely built a house, but He that builds all things; God: through Whom for Whom and by Whom all things are.

The house of Moses is set up as a contrast with the house of Christ: the former house being the law, the latter being grace and truth.
If the former house, built by servants to serve in, could have produced righteousness then the latter house would have been unnecessary - but God Who built all things purposed a house in which He Himself would dwell with us, bringing us mercy and peace and life.
That house is Christ, it is Salvation, it is He in us and we in Him.

When a great palace is being built, first a temporary place for the workers is set up. When that castle is complete, the houses of the workers are taken away, and a garden is planted there, for the Master of the house to walk in, and to enjoy its fruit.

"The House" is another synonym for the Temple/Tabernacle...
As when we get to heaven we will be tabernacling.

The Hebrews of the last days, the house of Israel. Hebrews serves as an amendment to the Mosaic covenant because a better covenant was established through the Jewish Messiah.

Is it the Jews only who have the confidence and firm hope of salvation in Christ through His faithful grace towards us revealed by His perfect propitiating sacrifice?

Hebrew means from across the river. We all will cross over on the day appointed for us.
A true Jew is not one of some man made denomination, no, a tru Jew is one who praises God in spirit and truth.
Israel, the one to come with the New Jerusalem, means to rule with God (El).
These understandings of what each is should help clear the water on the subject.

Only those who believe are true Jews. Beware of those who say they are Jews but are not, rather they are a congregation of Satan. It is also said, synagogue of Satan, .

Of course not, but that's not what the verse states. Is that verse true for the Jews in the last days? Do we, as part of the body of Christ, have to endure to the end?

.

I fully expect to be whisked off to a quarantine facility upon arrival where I'll
undergo intensive Bible instruction to correct all my mistakes and fill in the
blanks. That's likely to prevent the debating and quarrelling in Heaven that
goes on around internet forums.

I also expect to undergo finishing, i.e. training in Heaven's etiquette so I
don't go about hurting people's feelings with thoughtless remarks and
insensitive comments.
_

if what is written is true of all who believe, then the house is not just the Jews, and not just the Jews of the last days.
the house is all who have part in Him; the house is the having-part-in-Him

one ((expressly singular)) gospel, to the Jew first, then also the Greek - to the ends of the world. Romans 1:16

endure in what?
in the confidence and steadfast sure hope we have in Him, specifically, in what He has done that accomplished our salvation forever, to the uttermost.
in faith. in belief in His faithfulness towards us to complete what He begun in us; in the certainty of our salvation because of His single perfect sacrifice.

bear in mind that vv. 1-6 of the text here are specifically contrasting the house that is through Moses to the house built by God which is in Jesus Christ: this is not just for Jews. it is salvation, and there is exactly one salvation

servanthood vs. sonship

compare:

These Jews can be part of the house if they hold fast, endure to the end. That's tribulation doctrine for the Jews...Jacob's Trouble.

Hebrews 3
8 Harden not your hearts, as in the provocation, in the day of temptation in the wilderness: Jews
9 When your fathers tempted me, proved me, and saw my works forty years. Jews
10 Wherefore I was grieved with that generation, and said, They do alway err in their heart; and they have not known my ways. Jews
11 So I sware in my wrath, They shall not enter into my rest.) Millennial reign, restoration of the kingdom of Israel
12 Take heed, brethren, lest there be in any of you an evil heart of unbelief, in departing from the living God.
13 But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin. Endure
14 For we are made partakers of Christ, if we hold the beginning of our confidence stedfast unto the end; Enduring to the end, see Matthew 24