Jn 4:9, 20-26, 40-42, Jn 17:21, Acts 2:43-47, Eph 2:12-18
In the Old Testament, God said that the Israelites from the north and the Jews from the south, who were scattered across the nations, would gather together and become one under one king, and all of them would become God's people. (Ezekiel 37:16-23)
Ezekiel 37:16 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: 17 And join them one to another into one stick; and they shall become one in thine hand. 18 And when the children of thy people shall speak unto thee, saying, Wilt thou not shew us what thou meanest by these? 19 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. 20 And the sticks whereon thou writest shall be in thine hand before their eyes. 21 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: 22 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. 23 Neither shall they defile themselves any more with their idols, nor with their detestable things, nor with any of their transgressions: but I will save them out of all their dwellingplaces, wherein they have sinned, and will cleanse them: so shall they be my people, and I will be their God.
The Israelites in the north worshiped God in Samaria, and the Jews in the south worship God in Jerusalem. Now, the Samaritans of northern Israel and the southern Jews can worship God through Jesus the Christ. (John 4:9,20-26,40-42)
John 4:9 Then saith the woman of Samaria unto him, How is it that thou, being a Jew, askest drink of me, which am a woman of Samaria? for the Jews have no dealings with the Samaritans. 20 Our fathers worshipped in this mountain; and ye say, that in Jerusalem is the place where men ought to worship. 21 Jesus saith unto her, Woman, believe me, the hour cometh, when ye shall neither in this mountain, nor yet at Jerusalem, worship the Father. 22 Ye worship ye know not what: we know what we worship: for salvation is of the Jews. 23 But the hour cometh, and now is, when the true worshippers shall worship the Father in spirit and in truth: for the Father seeketh such to worship him. 24 God is a Spirit: and they that worship him must worship him in spirit and in truth. 25 The woman saith unto him, I know that Messias cometh, which is called Christ: when he is come, he will tell us all things. 26 Jesus saith unto her, I that speak unto thee am he. 40 So when the Samaritans were come unto him, they besought him that he would tarry with them: and he abode there two days. 41 And many more believed because of his own word; 42 And said unto the woman, Now we believe, not because of thy saying: for we have heard him ourselves, and know that this is indeed the Christ, the Saviour of the world.
If we believe in Jesus as the Christ, we all become one. (John 17:21)
John 17:21 That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me.
By believing in Jesus as the Christ, we are all one. (Acts 2:43-47)
Acts 2:43 And fear came upon every soul: and many wonders and signs were done by the apostles. 44 And all that believed were together, and had all things common; 45 And sold their possessions and goods, and parted them to all men, as every man had need. 46 And they, continuing daily with one accord in the temple, and breaking bread from house to house, did eat their meat with gladness and singleness of heart, 47 Praising God, and having favour with all the people. And the Lord added to the church daily such as should be saved.
When Jews and Gentiles believe in Jesus as the Christ, they become one. (Eph 2:12-18)
Eph 2:12 That at that time ye were without Christ, being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world: 13 But now in Christ Jesus ye who sometimes were far off are made nigh by the blood of Christ. 14 For he is our peace, who hath made both one, and hath broken down the middle wall of partition between us; 15 Having abolished in his flesh the enmity, even the law of commandments contained in ordinances; for to make in himself of twain one new man, so making peace; 16 And that he might reconcile both unto God in one body by the cross, having slain the enmity thereby: 17 And came and preached peace to you which were afar off, and to them that were nigh. 18 For through him we both have access by one Spirit unto the Father.