Devotee: svalpam apy asya dharmasya trayate mahato bhayat. We have heard you explain that mahabhaya means the fear of loosing the service of Vaishnava and Guru. But in general Bhagavad Gita meaning, mahabhaya means punaravritti (rebirth).
Swami B. R. Sridhara: But even that which is not punaravritti - brahma-pradesh, viraja, samadrishta, that is also bhaya (fear) to the proper soul. To the soul proper the apprehension is not only of birth and death but also of incarceration into brahman. Bhukti-mukti-sprha pishachi - mukti is also bhaya. So, exploitation is birth and death, and renunciation is full stop of birth and death, but not a life in the positive, both bhoga (exploitation) and tyaga (renunciation), are bhaya. Sayujya-mukti is where there is no birth and death, but permanent burial into brahma-loka.
bhukti-mukti spriha yavat pishachi hridi vartate
tavad bhakti sukhasyatra katham abhyudayo bhavet
As long as the witches of enjoyment and renunciation remains in one's heart, how can the happiness of Bhaki arise there. - Bhakti Rasamrita Sindhu 1.2.22
anyabhilashita shunyam jnana-karmady anavritam
anukulyena krishnanushilanam bhaktiruchyate
Bhakti means accepting things that are favorable to the service of Krishna without a tinge of speculation (jnana), materialistic endeavors (karma), or independent desires. - Bhakti Rasamrita Sindhu 1.1.11
Brahma-loka, brahma-sajuya, is more dangerous than this ordinary life of action and reaction. Mahabhaya means apprehension. This is bhoga bhumi (exploitation) and that is tyaga-bhumi (renunciation). Tyaga is more dangerous. So, mahabhaya means fear of not only birth and death, but also of eternal merging into the non-differentiated consciousness, brahmaloka or viraja. That is also bhaya.
Krishna is abhaya - beyond apprehension. By participation in His service there is no fear. Otherwise, mukti is like a strike in the organic system. That must be avoided. We have no right to misuse/abuse the service in a factory, or to declare a strike, that is cessation of service - both are abnormal. Bhukti-mukti spriha, pishachi hridi vartate. So, if we remove bhukti and mukti, then only the positive bhakti is the remainder. So, without bhakti, all is mahabhaya - great danger.
pratyavayo na vidyate
svalpam apy asya dharmasya
trayate mahato bhayat
In this activity there is no loss, nor is there any diminution of result. Even the slightest effort performed righteously saves one from the greatest fear. - Bhagavad Gita 2.40
Trayate mahato bhayat - From the mahabhaya of life and death, as well as the cessation - that is sayujya-mukti (liberation into the non-differentiated). Liberation proper is to become devoted. To enter into the non-differentiated is to commit suicide into the one non-differentiated consciousness. Impersonal, to merge into the impersonal position. To be the prey of exploitation and renunciation is our apprehension, and we are to save ourselves from these two alternative dangers: bhukti and mukti.