Krsna is all-attractive, but pure devotional service attracts even Him. This means that pure devotional service is even transcendentally stronger than Krsna Himself, because it is Krsna's internal potency.

His Divine Grace A.C. Bhaktivedanta Swami Prabhupada
The Nectar of Devotion, p. 4

Those who fix their minds on My personal form and are always engaged in worshiping Me with great and transcendental faith are considered by Me to be most perfect.

Lord Sri Krsna
Bhagavad-gita 12.2

The wise inhabitants of the heavenly regions know that the perfection of the head is to offer obeisances to the Supreme Lord, the perfection of the life-breath is to worship the Lord, the perfection of the mind is to ponder the details of His transcendental qualities, and the perfection of speech is to chant the glories of His qualities.

King Kulasekhara Alvar
Mukunda-mala-stotra 46

What is difficult to achieve for determined men who have taken refuge of the Supreme Personality of Godhead's lotus feet? His feet are the source of sacred rivers like the Ganges, which put an end to the dangers of mundane life.

Sri Maitreya Rsi
Srimad-Bhagavatam 3.23.42

Of all types of worship, worship of Lord Visnu is best, and better than the worship of Lord Visnu is the worship of His devotee, the Vaisnava.

Lord Siva, Padma Purana

It has been conclusively decided in the scriptures, after due consideration, that the ultimate goal for the welfare of human society is detachment from the bodily concept of life and increased and steadfast attachment for the Supreme Lord, who is transcendental, beyond the modes of material nature.

Prthu Maharaja
Srimad-Bhagavatam 4.22.21

The service of Truth is the function of the soul.

Srila Bhaktisiddhanta Sarasvati Thakura
Search for Truth (essay)