To follow the instructions of the Lord is to associate with the Lord. The Lord is not a material object whose presence one has to feel for such association. The Lord is present everywhere and at all times. It is quite possible to have His association simply by following His instruction because the Lord and His instruction and the Lord and His name, fame, attributes, and paraphernalia are all identical with Him, being absolute knowledge.
His Divine Grace A. C. Bhaktivedanta Swami Prabhupada
Srimad-Bhagavatam 1.12.24, Purport

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.
Hari-bhakti-sudhodaya (from Narada Purana)
Quoted in Chaitanya-charitamrita, Madhya-lila 23.23

O Lord, I do not pray for heavenly happiness. I do not even aspire for liberation. Simply let the nectar of Krishna’s transcendental pastimes flood my ears day after day.
Sri Kaviratna
Srila Rupa Goswami’s Padyavali (40)

O best of kings, one who is faithful, who is always hearing the glories of the Supreme Personality of Godhead, who is always engaged in the culture of Krishna consciousness and in hearing of the Lord’s activities, very soon becomes eligible to see the Supreme Personality of Godhead face to face.
Sri Narada Muni
Srimad-Bhagavatam 4.29.38

By refraining from a particular sinful or materialistic activity, one becomes freed from its bondage. Such renunciation is the basis of religious and auspicious life for human beings and drives away all suffering, illusion, and fear.
Lord Sri Krishna
Srimad-Bhagavatam 11.21.18

Without devotional service, all other methods for spiritual self-realization are weak and insignificant. Unless one comes to the devotional service of Lord Krishna, jnana and yoga cannot give the desired results.
Sri Chaitanya Mahaprabhu
Sri Chaitanya-charitamrita, Madhyalila 22.18

When the spirit soul (jiva) gives up the illusory relationship with matter and cultivates its eternal relationship with Krishna, a boundless joy that is characteristic of its own pure consciousness arises in its being. That is the natural happiness of the jiva.
Srila Bhaktivinoda Thakura
Vaishnava-siddhanta-mala, Chapter 6

As soon as we learn about the truth, we should become fixed in it. We should not waste even a moment of the time we have left in our lives on sense gratification. Rather, we should use all our time to worship Hari [Krishna].
Srila Bhaktisiddhanta Sarasvati Thakura
108 Essential Instructions (No. 33)