Religion without philosophy is sentiment, or sometimes fanaticism, while
philosophy without religion is mental speculation.
—His Divine Grace A.C. Bhaktivedanta Prabhupada
Bhagavad-gita As It Is 3.3, Purport
All kinds of activities, both auspicious and inauspicious, that are
detrimental to the discharge of transcendental loving service to
Lord Sri Krishna are actions of the darkness of ignorance.
- Krishnadasa Kaviraja Goswami
Sri Chaitanya-caritamrta, Adi-lila 1.94
Even though one may be very learned and wise, he is mad if he does not
understand that the endeavor for sense gratification is a useless
waste of time. Being forgetful of his own interest, he tries
to be happy in the material world, centering his interests
on his home, which is based on sexual intercourse
and which brings him all kinds of material
miseries. In this way one is no better
than a foolish animal.
- Lord Rsabhadeva
Srimad-Bhagavatam 5.5.7
Sri Krishna, the Personality of Godhead, who is the Paramatma [Supersoul]
in everyone's heart and the benefactor of the truthful devotee, cleanses
desire for material enjoyment from the heart of the devotee
who has developed the urge to hear His messages,
which are in themselves virtuous when
properly heard and chanted.
- Suta Goswami
Srimad-Bhagavatam 1.2.17
Whatever a devotee experiences he should consider to be an expansion of Krishna.
Thus seeing everything that exits within creation as the body of the
Supreme Lord, Hari, the devotee should offer his sincere
respects to the entire expansion of the Lord's body. - Kavi Rsi
Srimad-Bhagavatam 11.2.41
Only unto those great souls who have implicit faith in both the Lord
and the spiritual master are all the imports of Vedic knowledge
automatically revealed.