The living entities are foreign to matter, and thus they cannot be happy unless they are situated in the same spiritual life as the Lord. The mistaken living being, out of forgetfulness of this original condition of life, unnecessarily wastes time trying to become happy in the material world. The whole Vedic process is to remind one of this essential feature of life.
His Divine Grace A. C. Bhaktivedanta Swami Prabhupada
Srimad-Bhagavatam 3.5.26, Purport

It is a Vaishnava’s business to induce all materialistic living entities to become inclined toward the Supreme Lord. This is real compassion. Our spiritual success is guaranteed if we are honest in our dealings with Vaishnavas, hear attentively from them, and lead our lives according to their instructions. Only then can we be said to be taking advantage of their association.
Srila Bhaktisiddhanta Sarasvati Thakura
Amrita-vani, “Association”

To understand the variegated nature of the spiritual world requires deep meditation. The variegated nature of the material world is temporary happiness and distress. The variegated nature of the spiritual world is vast and full of spiritual bliss.
Srila Bhaktivinoda Thakura
Commentary on Brahma-samhita 5.56

Having achieved this human form of life, which affords one the opportunity to realize Me, and being situated in My devotional service, one can achieve Me, the reservoir of all pleasure and the Supreme Soul of all existence, residing within the heart of every living being.
Lord Sri Krishna
Srimad-Bhagavatam 11.26.1

The manifestation of unadulterated devotional service is exhibited when one’s mind is at once attracted to hearing the transcendental name and qualities of the Supreme Personality of Godhead, who is residing in everyone’s heart. Just as the water of the Ganges flows naturally down towards the ocean, such devotional ecstasy, uninterrupted by any material condition, flows towards the Supreme Lord.
Lord Kapila
Srimad-Bhagavatam 3.29.11–12

Sri Sri Radha-Krishna are the Lords of my life. They are my only goal in life or death. Those who worship the divine couple enjoy transcendental mellows and float always in the ocean of love of God. Let this fact ever remain in my heart.
Narottama Dasa Thakura
Prema-bhakti-chandrika 4.3

O Lord, in this birth I have not meditated on You, glorified You, even slightly worshiped You, or developed any devotion to Your lotus feet. That is why I suffer in this condition. I am very poor and fallen. O Sri Krishna, O ocean of mercy, please be compassionate on me.
Sri Sankara
Srila Rupa Goswami’s Padyavali 68