Everyone has a tendency to love someone. That Krishna should be the object of love is the central point of Krishna consciousness. By constantly chanting the Hare Krishna mantra and remembering the transcendental pastimes of Krishna, one can be fully in Krishna consciousness and thus make his life sublime and fruitful.
His Divine Grace A. C. Bhaktivedanta Swami Prabhupada
Krishna, the Supreme Personality of Godhead, Chapter 35

A person who gives up all fruitive activities and offers himself entirely unto Me, eagerly desiring to render service unto Me, achieves liberation from birth and death and is promoted to the status of sharing My own opulences.
Lord Sri Krishna
Srimad-Bhagavatam 11.29.34

Pranava, or omkara, is an indirect name of Krishna, the original sound of the Vedas, shabda brahma. The noun pranava is formed from the verb pranu (“to sound”), made from the prefix pra (“very much”) and the verb nu (“to praise”). Therefore pranava, or omkara, is the sound incarnation of the Supreme Brahman, the person worthy of our praise and worship.
Srila Bhaktivinoda Thakura
Sri Chaitanya Sikshamrita, Chapter One, Part 5

In this Kali-yuga, of what use is a collection of hundreds or thousands of other scriptures in the home of someone who does not have the scripture Bhagavatam?
Skanda Purana, Vishnu-khanda 5.16.40

When transcendental devotional service, by which love for Krishna is attained, is executed by the senses, it is called sadhana-bhakti, or the regulative discharge of devotional service. Such devotion eternally exists within the heart of every living entity. The awakening of this eternal devotion is the potentiality of devotional service in practice.
Srila Rupa Goswami
Bhakti-rasamrita-sindhu 1.2.2

With their words, they offer prayers to the Lord. With their minds, they always remember the Lord. With their bodies, they offer obeisances to the Lord. Despite all these activities, they are still not satisfied. This is the nature of pure devotees. Shedding tears from their eyes, they dedicate their whole lives to the Lord’s service.
Quoted in Chaitanya-charitamrita, Madhya 23.23

We can accept either that which is immediately appealing (preyas) or that which is permanently beneficial (shreyas). The wise, after careful consideration, accept that which is enduringly salutary, whereas those whose judgment is poor prefer fleeting gain and pleasure.
Katha Upanishad 1.2.2