Progress in the spiritual path
Kaivalya Upanishad mentions this topic with a concept called “Sarvatma Bhava”
Saguna is worshiping God with form.
Nirguana is worshiping God without form.
Experiencing own self in all beings is called “Sarvatma Bhava”
If we achieve the above then success, either through the practice of worshiping Saguna or Nirguna Brahman.
Here below link for a complete pdf of Kaivalya Upanishad.
Here below video of Kaivalya Upanishad.