God's Purpose

And we know that in all things God works for the good of those who love him, who have been called according to his purpose. For those God foreknew he also predestined to be conformed to the likeness of his Son, that he might be the firstborn among many brothers. (Romans 8:28,29)
What is God's eternal purpose? It is to create brothers of the Lord Jesus Christ. Have you ever heard this preached? Neither have I.
Why would God want brothers for His Son? Maybe for fellowship. Maybe because God is going to create an eternal kingdom in the ages to come, with populations on numerous stars as well as on the new earth---stars that shine with the Glory of Christ. Obviously these branches of the one Kingdom will need rulers.
Maybe because God wants to enlarge His family of sons. Maybe because God is so pleased with the Lord Jesus He wants to multiply His image, His Person.
Will these be genuine brothers, or is this some kind of churchy figure of speech?
I believe they will be genuine brothers, born of the same Father. The Bible refers to the Lord Jesus as the Firstborn.
In bringing many sons to glory, it was fitting that God, for whom and through whom everything exists, should make the author of their salvation perfect through suffering. Both the one who makes men holy and those who are made holy are of the same family. So Jesus is not ashamed to call them brothers. (Hebrews 2:10,11)