Light and Darkness, life and death, right and left, are brothers of one another. They are inseparable. Because of this neither are the good good, nor evil evil, nor is life life, nor death death. For this reason each one will dissolve into its earliest origin. But those who are exalted above the world are indissoluble, eternal. (Gospel of Philip).
If you keep reading the gnostic gospels every so often the authors reveal the key to understanding the sayings.
This verse is one of the up front verses.
The opposites are duality. Philip is talking plainly about duality.
The dual opposites dissolve into the formless god nature being the origin.
Being exalted means to be aligned to the god nature hence indissoluble and not the universe (sophia) which is dissoluble.