Śrīla Bhaktisiddhānta Sarasvatī Ṭhākura Prabhupāda
Question : How should the devotee behave while living in this world?
Answer: Although people around him will invariably engage in mundane conversations, he should not listen to such discussions. When a person is determined to move forward on his own dutiful path, nothing harmful can hinder him. He should offer respect to those who are averse to bhakti, but should not come to honour their behaviour. Rather, he should renounce it within the core of his heart.
When he has time, he should deliberate on books like Śaraṇāgati, Prārthana and Prema-bhakti-candrika. It is better to have śāstriya-sādhu-saṅga (saintly association through authentic scripture) than no sādhu-saṅga at all. Later, for instruction in the art of internal, transcendental service (bhajana-śikṣā), direct sādhu-saṅga is necessary.
from Śrīla Prabhupādera Upadeśāmṛta