Because Bhagavad Gita is spoken by the Supreme Personality of Godhead, one need not read any other Vedic literature. One need only attentively and regularly hear and read Bhagavad Gita.
Bhagavad Gita Introduction,
Krishna may crush our ego, pulverize it, crush it to powder, make it into granules. Do we still continue to remain faithful to Krishna?
"Accept Krishna as your friend. You will be happy." This is the message of Krishna Consciousness.
Civilization and Transcendence,
Of all sacriﬁces, the chanting of Hare Krishna, Hare Krishna, Krishna Krishna, Hare Hare/ Hare Rama, Hare Rama, Rama Rama, Hare Hare is the purest representation of Krishna.
The highest summit of spiritual perfection is knowledge of the Supreme Personality of Godhead.
Bhagavad Gita 10.7,
If one makes friendship with Krishna, one will never be cheated and he will get all help needed.