Thanks for the question. It has come up before but not very often to be honest. There are more qualified people to speak on it (and I'll include a couple of links at the bottom) but I'll let you know what I believe.
Let me start with a quick definition for other readers... The "lost tribes of Israel" is a reference to the so-called lost 10 northern tribes of Israel that went into the Assyrian captivity from 740 to 722 BC.
These were the tribes of Reuben, Simeon, Levi, Dan, Naphtali, Gad, Asher, Issachar, Zebulun, and Joseph (which divided into the tribes of Ephraim and Manasseh). Scripture says:
2Ki 17:6 In the ninth year of Hoshea, the king of Assyria captured Samaria and deported the Israelites to Assyria. He settled them in Halah, in Gozan on the Habor River and in the towns of the Medes.
Some believe these tribes were then "lost" and various theories have been floated as to who and where they are now. For example the Mormons, starting with Joseph Smith, falsely believed that the lost tribes found their way to America. "British Israel" is another false theory that believes the people of Great Britain are descendants from the lost tribes of Israel.
You asked how JPN views the lost tribes...
Firstly there is biblical evidence that not everyone from these tribes were taken into captivity in the first place. Many from these tribes had already traveled into the southern Kingdom of Judah prior to the Assyrian captivity, and thus were not part of the Assyrian captivity:
1Ki 12:16-17 When all Israel saw that the king refused to listen to them, they answered the king: "What share do we have in David, what part in Jesse's son? To your tents, O Israel! Look after your own house, O David!" So the Israelites went home. (17) But as for the Israelites who were living in the towns of Judah, Rehoboam still ruled over them.
Further evidence that not all went into captivity is seen in the days of King Hezekiah (which is post Assyrian captivity), where the King issued a call to all the tribes of Israel for them to come and celebrate the Passover. So clearly these tribes were not completely "lost" as they still existed in Israel:
2Ch 30:5 They decided to send a proclamation throughout Israel, from Beersheba to Dan, calling the people to come to Jerusalem and celebrate the Passover to the LORD, the God of Israel. It had not been celebrated in large numbers according to what was written.
Scripture also talks about 'the remnant of Israel' and the people of 'Manasseh, Ephraim' that remained in the land post-Assyrian captivity in the days of King Josiah:
2Ch 34:6-9 In the towns of Manasseh, Ephraim and Simeon, as far as Naphtali, and in the ruins around them, (7) he tore down the altars and the Asherah poles and crushed the idols to powder and cut to pieces all the incense altars throughout Israel. Then he went back to Jerusalem. (8) In the eighteenth year of Josiah's reign, to purify the land and the temple, he sent Shaphan son of Azaliah and Maaseiah the ruler of the city, with Joah son of Joahaz, the recorder, to repair the temple of the LORD his God. (9) They went to Hilkiah the high priest and gave him the money that had been brought into the temple of God, which the Levites who were the doorkeepers had collected from the people of Manasseh, Ephraim and the entire remnant of Israel and from all the people of Judah and Benjamin and the inhabitants of Jerusalem.
The New Testament
When you get to the New Testament it speaks of different people that belonged to some of the so-called "lost tribes" (which are clearly not lost) such as:
Luk 1:5 In the time of Herod king of Judea there was a priest named Zechariah, who belonged to the priestly division of Abijah; his wife Elizabeth was also a descendant of Aaron.
Luk 2:36 There was also a prophetess, Anna, the daughter of Phanuel, of the tribe of Asher. She was very old; she had lived with her husband seven years after her marriage
Act 4:36 Joseph, a Levite from Cyprus, whom the apostles called Barnabas (which means Son of Encouragement),
Also Jesus said "I was sent only to the lost sheep of Israel." - And by that He meant the whole nation of all twelve tribes. Jesus never spoke of the tribes being lost. Paul also speaks, in the present tense, of all twelves tribes existing and serving God:
Act 26:7 This is the promise our twelve tribes are hoping to see fulfilled as they earnestly serve God day and night. O king, it is because of this hope that the Jews are accusing me.
Further, when Jesus spoke of the future He spoke about the disciples ruling over the 12 tribes... so again, 10 tribes aren't "lost" - they exist:
Mat 19:28 Jesus said to them, "I tell you the truth, at the renewal of all things, when the Son of Man sits on his glorious throne, you who have followed me will also sit on twelve thrones, judging the twelve tribes of Israel.
And when we get to the book of Revelation we see that in the future, God will set aside 12,000 from each of the 12 tribes (Rev 7:4-8) So again, none are lost. God knows exactly who is who even if we don't! Even though there were many from all 12 tribes that were scattered abroad in the Assyrian captivity and the Babylonian captivity, and then again in the Roman sacking of Israel/Jerusalem in 70AD, the fact remains that even these are not lost to God. He has brought many back to the land of Israel in our day (from a wide variety of nations such as Russia, India, Ethiopia etc) in fulfillment of scripture and will continue to do so. One such prophecy (amongst many) of the Israelites coming back is:
Eze 37:21-22 and say to them, 'This is what the Sovereign LORD says: I will take the Israelites out of the nations where they have gone. I will gather them from all around and bring them back into their own land. (22) I will make them one nation in the land, on the mountains of Israel. There will be one king over all of them and they will never again be two nations or be divided into two kingdoms.
So even for those that are still scattered among many different nations today, God knows exactly who they are, which tribe they belong to, and will bring them back. None are lost.
Should pastors teach on it, even if the teachings and research takes you beyond the Bible?
The short answer would be 'no'. I mean they may want to research it themselves and teach some of the false theories that have arisen so that the flock have an understanding of it, are equipped should it come up, and realise that God is miraculously bring the Israelites back into their land in fulfillment of scripture. But they shouldn't be teaching that the tribes are lost or going after the many various myths surrounding this topic. They should be feeding the flock good food! Food that the New Testament focuses on. Ask yourself some questions:
- Did Jesus focus on the lost tribes at all? No He didn't. Not at all. That should be a red flag straight away.
- Did Jesus even mention the lost tribes? No He didn't. He spoke of all 12 tribes as shown above.
- Did Paul teach or say that some tribes were lost? No. He spoke of all 12 tribes in existence as shown above. He also said he was from the tribe of Benjamin (which was in the southern kingdom of Judah) and in the same verse calls himself an Israelite (Rom 11:1) - so he didn't draw a distinction between the two kingdoms.
- Is there anything in the New Testament teaching about 'lost tribes'? No. James addresses his epistle to 'the twelve tribes scattered among the nations' but this is to do with those from all 12 tribes who were still out of the land. He knew the twelves tribes still existed even if some weren't in the land. God knows who and where they are.
- Should Pastors be focusing on things that don't have biblical support requiring them to go to other sources? Again, in general, no. The New Testament warns against going after myths (1Tim 1:4, 1Tim 4:7, Tit 1:14). Instead Pastors should be focusing on that which the New Testament focuses on. They should be preaching the Bible and equipping the sheep. As he approached the end of his life, here is Paul's advice to a young leader Timothy which is just as true today:
2Ti 4:1-3 In the presence of God and of Christ Jesus, who will judge the living and the dead, and in view of his appearing and his kingdom, I give you this charge: (2) Preach the Word; be prepared in season and out of season; correct, rebuke and encourage--with great patience and careful instruction. (3) For the time will come when men will not put up with sound doctrine. Instead, to suit their own desires, they will gather around them a great number of teachers to say what their itching ears want to hear.
'The lost tribes' is one of those 'rabbit hole' topics that you can go down and soon find yourself going in lots of directions, reading all sorts of whacky theories. It isn't helpful. None are lost to God.
I would also direct you to the following resources if you would like to know more:
I hope this helps. All the best,