Rishis will Reinstitute the Sanatan Dharma if Diluted (SB 8/14/4)

चतुर्युगान्ते कालेन ग्रस्ताञ्छ्रुतिगणान्यथा – तपसा ऋषयोऽपश्यन्यतो धर्म: सनातन:

At the end of the four Yugas, when, the knowledge of Vedas are diluted (destroyed), the Seers, by their asceticism visualise them (again), from which the Eternal Dharma ensues.

चतुर्युगान्ते कालेन ग्रस्ताञ्छ्रुतिगणान्यथा ।
तपसा ऋषयोऽपश्यन्यतो धर्म: सनातन: ॥ ४ ॥-श्रीमद्भागवत

chatur-yugante kalena
grastaa sruti-gaṇan yatha
tapasa ṛiṣayo pasyanto
yato dharmaḥ sanatanaḥ

चतु: युग अन्ते कालेन ग्रस्तान् श्रुतिगणान् यथा – तपसा ऋषय: अपश्यन् यत: धर्म: सनातन:

Translation

At the end of every four yugas, the great Rishis, upon seeing that the eternal occupational duties of mankind have been misused, reestablish the principles of Sanatan Dharma.

प्रत्येक चार युगों के अन्त में महान् सन्तपुरुष जब यह देखते हैं कि मानव के शाश्वत वृत्तिपरक कर्तव्यों का दुरुपयोग हुआ है, तो वे धर्म के सिद्धान्तों की पुन:स्थापना करते हैं।

Manusmriti (4-138), … “Satyam bruyatpriyam bruyanna bruyatsatyamapriyam. Priyam cha nanrtam bruyadesa dharmah sanatanah.” (Translation: “Speak the truth, speak the truth that is pleasant. Do not speak the truth to manipulate. Do not speak falsely to please or flatter someone. This is the quality of the eternal dharma”) …

Purport

In this verse, the words dharmaḥ and sanātanaḥ are very important. Sanātana means “eternal,” and dharma means “occupational duties.” From Satya-yuga to Kali-yuga, the principles of Dharma and occupational duty gradually deteriorate. In Satya-yuga, the religious principles are observed in full, without deviation. In Tretā-yuga, however, these principles are somewhat neglected, and only three fourths of the religious duties continue. In Dvāpara-yuga only half of the Dharmic principles continue, and in Kali-yuga only one fourth of the Dharmic principles, which gradually disappear. At the end of Kali-yuga, the principles of Sanatan Dharma, or the occupational duties of humanity, are almost lost. Indeed, in this Kali-yuga we have passed through only five thousand years, yet the decline of sanātana-dharma is very prominent. The duty of saintly persons, therefore, is to take up seriously the cause of sanātana-dharma and try to reestablish it for the benefit of the entire human society. The Kṛṣṇa consciousness movement has been started according to this principle. As stated in Śrīmad-Bhāgavatam (12.3.51):

धाम्ना स्वेन सदा निरस्त-कुहकम् सत्यम् परम् धीमहि

कलेर्दोषनिधे राजन्नस्ति ह्येको महान् गुण:।

कीर्तनाद् एव कृष्णस्य मुक्तसङ्ग: परं व्रजेत् ॥

The entire Kali-yuga is full of faults. It is like an unlimited ocean of faults. But the Kṛṣṇa consciousness movement is very authorized. Therefore, following in the footsteps of Srī Chaitanya Mahaprabhu, who five hundred years ago inaugurated the movement of saṅkīrtana, kṛṣṇa-kīrtana, we are trying to introduce this movement, according to superior orders, all over the world. Now, if the inaugurators of this movement strictly follow the regulative principles and spread this movement for the benefit of all human society, they will certainly usher in a new way of life by reestablishing sanātana-dharma, the eternal occupational duties of humanity. The eternal occupational duty of the human being is to serve Kṛṣṇa. Jīvera ‘svarūpa’ haya-kṛṣṇera ‘nitya-dāsa.’ This is the purport of sanātana-dharma (सनातन धर्म). [AC Bhakti Vedanta Swami]

यदा यदा हि धर्मस्य ग्लानिर्भवति भारत।
अभ्युत्थानमधर्मस्य तदात्मानं सृजाम्यहम् ॥४-७॥ Gita

परित्राणाय साधूनां विनाशाय च दुष्कृताम् ।
धर्मसंस्थापनार्थाय सम्भवामि युगे युगे ॥४-८॥ Gita

परित्राणाय साधूनां विनाशाय च दुष्कृताम् धर्मसंस्थापन अर्थाय सम्भवामि युगे युगे