Srimad Bhagavad-Gita :
Chapter-12. ( Bhakti-yogam)
Slokam - 5. (For those whose minds are attached to the unmanifested, impersonal feature of the Supreme, advancement is very troublesome. To make progrese in that discipline is always difficult for those who are embodied.)
Superior to prakiti the material substratum underlying physical existence is the brahman the spiritual substratum pervading all existence and superior to the brahman is atma tattva and superior to atma tattva is communion with the Supreme Lord Krishna Himself.
The Agnivesya section has clarified the same stating: Without beginning and without end is the brahman etrnally existing and the Supreme Lord is superior to even the brahman.
Vedavyasa the author of Brahma Sutra has explained there that knowledge of the Supreme Lord alone is the only way to achieve moksham.
One may interject that if the followers of the abstract, impersonal and imperishable brahman also attain the Supreme Lord anyway then what is the superiority of personal loving devotion to Lord Krishna.
Here the distinction is given that worshipping the abstract unmanifest, impersonal brahman is very difficult and requires excessive tribulation.
This is because one who only contemplates something abstract and unmanifest can never envision what they are unable to perceive and thus the mind is not able to realise it and is only rarely achieved with great difficulty in a very complex way because for those identifying with the mind, body and senses, internal introspection which is required for atma-tattva or self-realisation is exceedingly difficult.
To be continued ...