Mulling over Soli Gloria Dei on the Reformation's anniversary

For a long time I only thought there were three solas. Three Reformation rallying cries: Sola Gratia! Sola Fide! Sola Scriptura! Grace alone. Faith alone. Scripture alone. It didn't seem to me that you could add to these.

But somewhere along the line I learned that there were two more: Solus Christus (Christ alone) and Soli Gloria Dei (To the glory of God alone.)

I am considering that fifth sola. What does it mean to live for the glory of God alone?