No..I can’t agree.... I will stick with the body of believers, made up of Jews and Christians..as the Bride of Christ...the Church.... Not Israel nor any lost Tribes.
Even so...Biblically there is not just one title that refers to the church, the church is called by many different names in scripture.......Church of God (1 Cor. 1:2 and numerous other passages) ....Church of the living God (1 Tim. 3:15) kingdom of his dear Son (Col. 1:13).... kingdom of Christ and of God (Eph. 5:5).... Assembly of God (alternate translation of Church = assembly) ... general assembly and church of the firstborn (Heb. 12:23).... Flock (Acts 20:28) Church (Acts 11:26 and many other passages).... body (Eph. 1:23 and numerous other passages) body of Christ (1 Cor. 12:27)..... kingdom of God (Col. 4:11 and many other passages) ....family of God, household of God, house of God (1 Tim. 3:15) The bride of Christ.
What makes a church authentic is that they were founded by Christ. What one chooses to call themselves is irrelevant. Anyone can choose to call themselves anything they want, but proves nothing at all. The Bible never indicates that the Church will have one specific name. .....
....It is a matter of ‘ownership’ not a title.
I think you will find that it was ALL founded by Yeshua. The OT 'congregation' and the NT 'assembly' or 'church' are one and the same thing. All of the things of Christianity - the offices, rites, and rituals - have a direct counterpart in Judaism (albeit that they differ greatly, which I attribute to Roman syncretism)... Every bit of it comes right out of the Jewish rabbinical and synagogue system.
My point in that is to say that the 'called out ones' from the OT are the same as the 'called out ones' in the NT... And are saved in exactly the same way.