There is a certain symmetry in the events of the First and Second Coming of Jesus Christ.
When Jesus came to John the Baptist to be baptized, John said to him:
– I have need to be baptized of thee, and comest thou to me?
Jesus was circumcised according to the Law, and He was the Son of God, a saint who does not need the baptism of repentance. However, Jesus Christ was baptized by John, and this was accompanied by a sign of the Spirit.
Today's faithful to God people on the contrary, as a rule, are uncircumcised, but they are all baptized. And all these saints do not need circumcision, just as Jesus Christ did not need baptism. However, those saints who are executing the mission entrusted to them to be messengers of Jesus Christ for Jews, they will be circumcised, for thus us to fulfil all righteousness.
Do all today's Christians have to come to Israel to become Jews there?
According to the Law, not all the harvested crop, but only its tenth part, should be brought to God. "Harvest" is all people saved by Jesus Christ. "Tithes of the harvest" are those who completely devote themselves to God, these are the ten lost tribes of Israel returned from the peoples.
We conditionally call them as the "ten lost tribes of Israel", because the Northern Kingdom (Israel) was taken into Assyrian captivity. In the Northern Kingdom, there were 10 of the 12 tribes of Israel.
In fact, the lost tribes of Israel are more correctly called:
Ephraim, and [for] all the house of Israel his companions
Moreover, thou son of man, take thee one stick, and write upon it, For Judah, and for the children of Israel his companions: then take another stick, and write upon it, For Joseph, the stick of Ephraim, and [for] all the house of Israel his companions:
And join them one to another into one stick; and they shall become one in thine hand.
And when the children of thy people shall speak unto thee, saying, Wilt thou not shew us what thou [meanest] by these?
Say unto them, Thus saith the Lord GOD; Behold, I will take the stick of Joseph, which [is] in the hand of Ephraim, and the tribes of Israel his fellows, and will put them with him, [even] with the stick of Judah, and make them one stick, and they shall be one in mine hand.
And the sticks whereon thou writest shall be in thine hand before their eyes.
And say unto them, Thus saith the Lord GOD; Behold, I will take the children of Israel from among the heathen, whither they be gone, and will gather them on every side, and bring them into their own land:
And I will make them one nation in the land upon the mountains of Israel; and one king shall be king to them all: and they shall be no more two nations, neither shall they be divided into two kingdoms any more at all:
(Ezekiel 37:16-23)
Because within the present Jewish people there are descendants of all the tribes of Israel, and in the "lost tribes" (Ephraim) there are also descendants of all the tribes of Israel.
Note that Ephraim's stick will be attached to the stick of Judah, and not vice versa!
Do you expect that the Christian religion will swallow up today's Jews? No!
The Jewish people will swallow Christians who will be messengers of Jesus Christ in Ezekiel's Temple.
For the curious: please read the book of Tobit, this is a parable.