1) Industrious Jeroboam

Jeroboam almost had it all. A legacy like David's
Seest thou a man diligent in his business? he shall stand before kings; he shall not stand before mean men. (Proverbs 22:29)
If we focus on modern understanding, we miss our Creator Architect's message.
And this was the cause.. Solomon built Millo, and repaired the breaches of the city of David his father. (1 Kings 11:27)
Solomon loved building. The Creator loves building.
And the man Jeroboam was a mighty man of valour: and Solomon seeing the young man that he was industrious, he made him ruler over all the charge of the house of Joseph. (1Kings 11:28)
Not only did Solomon see the hard physical valorous labour in the work of Jeroboam, so did Yahweh Elohim the God of Israel. Solomon was making great building works, and Jeroboam, of Ephraim, was so hardworking, he is promoted to leadership in making those works, promoted to lead all the house of Joseph (Ephraim and Manasseh), the two most powerful tribes.
Then in standing before Solomon, and still working hard - he comes to challenge the power of Solomon, who was slipping into sloth, idolatry and folly. Jeroboam is told by the prophet Ahijah
that the kingdom is to be Solomon's until his death and even then his son is to have the tribe of Judah and David's family line is to be a light in Jerusalem. However,
It shall be, if thou wilt hearken unto all that I command thee, and wilt walk in my ways, and do that is right in my sight, to keep my statutes and my commandments, as David my servant did; that I will be with thee, and build thee a sure house, as I built for David, and will give Israel unto thee (1Kings 11:38)
For us, as Jeroboam, the promise is the same. We are offered by the Great Architect a house now and into forever – IF!
Jeroboam goes into Egypt to escape Solomon. Despite Solomon having taken Pharaoh's daughter to wife, Egypt seemed a popular place for anti-Solomon conspirators. Perhaps it wasn't to Jeroboam's good to go there. Perhaps he forgot to work.
There is no doubt Jeroboam's labour made him strong in leadership as when Solomon died, Jeroboam comes out of Egypt and stands before King Rehoboan Solomon's son. He takes the Northern Kingdom as prophesied, Rehoboam and Judah are told not to fight their brethren.
Then Jeroboam forgot what he had built in Jerusalem,
Then Jeroboam built Shechem in mount Ephraim, and dwelt therein; and went out from thence, and built Penuel. (1Kings 12:25)
If he had trusted at this point, and built his kingdom- we do not know where it would have ended. But
Jeroboam said in his heart, Now shall the kingdom return to the house of David: If this people go up to do sacrifice in the house of the LORD at Jerusalem, then shall the heart of this people turn again unto their lord, even unto Rehoboam king of Judah, and they shall kill me, and go again to Rehoboam king of Judah. (1Kings 12:26-27)
So Jeroboam builds gold calves and altars at Dan and Bethel. And loses his house.

Go, tell Jeroboam, Thus saith the LORD God of Israel, Forasmuch as I exalted thee from among the people, and made thee prince over my people Israel, And rent the kingdom away from the house of David, and gave it thee: and yet thou hast not been as my servant David, who kept my commandments, and who followed me with all his heart, to do that only which was right in mine eyes; But hast done evil above all that were before thee: for thou hast gone and made thee other gods, and molten images, to provoke me to anger, and hast cast me behind thy back: Therefore, behold, I will bring evil upon the house of Jeroboam, and will take away the remnant of the house of Jeroboam. (1 Kings 14:7-10)
Ironically, he lost and Judah gained the people who wished to continue true worship. If he had held, his may have been a golden age where Rehoboam might have served him, rather than there being warfare.
Jeroboam almost had a legacy like David's – a great and eternal house. What is that house? A Part of the lineage of the Messiah and an eternal part in the great House being made by God – to see his son reign forever before himself, to see Jerusalem built by the great architect and the greater than Solomon (Matt 12:42), as a city of peace, greater far than his zealous work to build Millo and Zion, the walls of King David's city (I Kings 8:1).