Bhagavad-gita is the instruction given by Krishna, and Srimad-Bhagavatam is the book containing topics exclusively about Krishna and His devotees. These two books are the special nectar of the words of Krishna.
Srimad Bhagavatam 4.4.44,
The right path to live on is to live with the right values and right universal character and to be an instrument of the grace within all of us.
It is not that everyone becomes purified by entering the Ganges. Everything, spiritual and material, depends on one’s mental condition.
The transcendental name of Krishna, even though uttered unconsciously or by force of circumstances, can help one obtain freedom from the hurdle of birth and death.
Srimad Bhagavatam 1.1.14,
Everyone is at liberty to desire as he likes, but the desire is fulfilled by the Supreme Lord.
Srimad Bhagavatam 3.4.11,
Everything is done by the supervision of the Supreme Personality of Godhead.
Srimad Bhagavatam 3.31.1,