What happens to Ephraim?

Matthew 12:25 And Jesus knew their thoughts, and said unto them, Every kingdom divided against itself is brought to desolation; and every city or house divided against itself shall not stand: 26 And if Satan cast out Satan, he is divided against himself; how shall then his kingdom stand?

Ephraim committed sin against GOD, by creating idols for worship, and were assimilated into other nations. I don't see anything in scripture saying that Ephraim will return and join Israel in its birthright.

Psalms 78:9 The children of Ephraim, being armed, and carrying bows, turned back in the day of battle. 10 They kept not the covenant of God, and refused to walk in his law; 11 And forgat his works, and his wonders that he had shewed them.

Psalms 78:66 And he smote his enemies in the hinder parts: he put them to a perpetual reproach. 67 Moreover he refused the tabernacle of Joseph, and chose not the tribe of Ephraim: 68 But chose the tribe of Judah, the mount Zion which he loved. 69 And he built his sanctuary like high palaces, like the earth which he hath established for ever.

In looking at the Book of Revelation, when the twelve tribes are mentioned, Ephraim is not among them.

Revelation 7:5 Of the tribe of Juda were sealed twelve thousand. Of the tribe of Reuben were sealed twelve thousand. Of the tribe of Gad were sealed twelve thousand. 6 Of the tribe of Aser were sealed twelve thousand. Of the tribe of Nephthalim were sealed twelve thousand. Of the tribe of Manasses were sealed twelve thousand. 7 Of the tribe of Simeon were sealed twelve thousand. Of the tribe of Levi were sealed twelve thousand. Of the tribe of Issachar were sealed twelve thousand. 8 Of the tribe of Zabulon were sealed twelve thousand. Of the tribe of Joseph were sealed twelve thousand. Of the tribe of Benjamin were sealed twelve thousand.