“If a living entity is developed in Krsna consciousness and is merciful to others, and if his spiritual knowledge of self-realization is perfect, he will immediately attain liberation from the bondage of material existence.”

PURPORT
In this verse the words daya jivesu, meaning mercy to other living entities, indicates that a living entity must be merciful to other living entities if he wishes to make progress in self-realization. This means he must preach this knowledge after perfecting himself and understanding his own position as an eternal servant of Krsna. Preaching this is showing real mercy to living entities. Other types of humanitarian work may be temporarily beneficial for the body, but because a living entity is spirit soul, ultimately one can show him real mercy only by revealing knowledge of his spiritual existence. As Caitanya Mahaprabhu says, jivera ‘svarupa’ haya-krsnera ‘nitya-dasa.’ [Cc Madhya 20.108]. “Every living entity is constitutionally a servant of Krsna.” One should know this fact perfectly and should preach it to the mass of people. If one realizes that he is an eternal servant of Krsna but does not preach it, his realization is imperfect. Srila Bhaktisiddhanta Sarasvati Thakura therefore sings, dusta mana, tumi kisera vaisnava? pratisthara tare, nirjanera ghare, tava hari-nama kevala kaitava. “My dear mind, what kind of Vaisnava are you? Simply for false prestige and a material reputation you are chanting the Hare Krsna mantra in a solitary place.” In this way people who do not preach are criticized. There are many Vaisnavas in Vrndavana who do not like preaching; they chiefly try to imitate Haridasa Thakura. The actual result of their so-called chanting in a secluded place, however, is that they sleep and think of women and money. Similarly, one who simply engages in temple worship but does not see to the interests of the mass of people, or cannot recognize devotees, is called a kanistha-adhikari:

arcayam eva haraye
pujam yah sraddhayehate
na tad-bhaktesu canyesu
sa bhaktah prakrtah smrtah
(SB 11.2.47)

A devotee who faithfully engages in the worship of the Deity in the temple but does not behave properly toward other devotees or people in general is called a prakrta-bhakta, a materialistic devotee, and is considered to be in the lowest position.

Srimad-Bhagavatam 4.29.1b, rendered by Srila Prabhupada