I'm not sure where you got your information (although this view does circulate among Catholics in particular). The early fathers were in fact Jewish fathers. These include Peter, James, John, Paul, etc. The first council (the Jerusalem Council) was comprised of Jewish fathers. When Protestants tried to figured out which books of scriptures were suppose to be included in the inerrant word of God, they went back to the Hebrew fathers for guidance. The idea that the earlier Gentile fathers were anti-semetics is nonsense. This comes from dispensationalists who attempt to discredit the idea that Gentiles have been grafted into Israel as is plainly stated in Romans 9. This is something early Gentile fathers taught as well as Paul.
Why does the church consider itself Israel? I can give you my understanding. The Israel of the scripture is a physical type for the spiritual church. It shows to the spiritual church all the good blessing of God as well as the consequences of sin. Part of Jewish believers (a remnant) made up Israel as well as Gentile believers (e.g. Caleb, Ruth, Rahab, etc.). This has been merged by God into the true Israel-the church, although there are still unbelievers (tares) within the framework of the church. It is not perfect-yet.
I believe the Old Testament to be woefully overlooked by today's church. These aren't "moral" stories but actual practice of living given to us by God. The OT acts of living are the doctrines of the NT put into the context of a living world. There are parallels between the physical Israel of yesteryear and the spiritual Israel of today.
why are we taught from the ‘church’ doctrines and traditions to reject everything that defines what a son or daughter is to look like and act like?
I'm not sure what you are talking about when you state that we are to reject everything that defines what a son or daughter should act like. And certainly most of the Protestants on this board would not agree that we are taught from "church" doctrines. We are constantly arguing about "sola scriptura" (scripture alone).
How we should act is laid out in scripture. Do justice. Love kindness. Walk humbly with God. Love God. Love one another. This is what defines us as sons/daughters of God. These are doctrinal values of the New Testament. How they are applied in the context of the living world can be found in the Old.
Yes, the fist leaders of “the Way” were Jewish, the 1st 50 and it wasn't until a gentile took the position that all was changed by the throwing out of what Messiah spoke and gave to us through Moses. They lived out Mt 6:10, ‘His will be done on earth as it is in the heavens’
Why do I believe that the religious systems teach differently? That is very clear in ALL their doctrines when they say because we are spiritual we do not have to obey what Moses wrote. Everything Moses wrote was about Messiah. the entire bible is about the Son who from the beginning in the garden, has been pointing and directing mankind back to the Father.
So why does the ‘church’ not practice this? Yeshua was rebuking the unbelieving Judeans, not because they searched the Scriptures, but because they missed the foundation that is taught in them, that foundation being it has ‘always’ been the Son speaking to mankind on behalf of the Father. He was stating to them that they had missed the point of Moses all together because their hearts were not grounded in the Messiah that Moses took all his dictation from.
So the way I see it, as it is the way Messiah taught it, we have to choices. We can follow Him as He follows the Father or we can choose to disobey and follow another that is not of the Father. One is Hebrew, the other is Roman as the anti-messiah rises out of Rome. If one is following all things that were put in place by the religious elite in Rome, can one truly know the Messiah? Scripture says not.
John 3:36 He who believes in the Son possesses everlasting life, but he who does not obey the Son shall not see life, but the wrath of Elohim remains on him.
Those commands give us His calendar and all that defines how we are to walk out every aspect of our daily lives, including when and how we are to worship the Father.
The doctrines of the NT are not new, they have been since the beginning. Love, kindness, humility, etc, etc are the core foundation of all that was given through Moses and Moses is replete. Something most in the ‘church’ system do not know because they do not take the role of Berean seriously is that in Mt 19 when Yeshua is speaking to the rich man is the fact that when He cites the commands to follow, He is not citing them from Ex 20, He is citing them from Leviticus 19 & 20. How many even know that the commands are given again in Leviticus?
There is nothing new in the NT, it is all simply true of what was to be, was is, and what is yet to be. The Scriptures of the Messiah speak nothing of a ‘new’ religious system that is to be separate from Israel. that is to look and walk differently from Israel. But until one humbles themselves, that is to say repent and then begin walking in His ways, one will never gain the knowledge, understanding of that knowledge and the wisdom to implement it. That is what Messiah is speaking of in regards to John 5:39-40.
When we put man's ways above the Way of the Father, we are blinded in part by the stone of stumbling, the stone that came to remove the ways of man and to teach us the pure, unadulterated path to the Father. The stone that is Messiah that was with them throughout the entire journey in the wilderness. (1 Cor 10:1-14 (see specifically v. 4,6,9,11-12,14))