It is said, vṛddhatvaṁ vayasā vinā: one may be senior without being advanced in age. Even if one is not old, one gains seniority if he is senior in knowledge. Viśvarūpa was junior in relationship to the demigods because he was their nephew, but the demigods wanted to accept him as their priest, and therefore he would have to accept obeisances from them. The demigods explained that this should not be a cause for hesitation; he could become their priest because he was advanced in Vedic knowledge. Similarly. Cāṇakya Paṇḍita advises, nīcād apy uttamaṁ jṣānam: one may accept education from a member of a lower social order. The brāhmaṇas, the members of the most elevated varṇa, are teachers, but a person in a lower family, such as a family of kṣatriyas, vaiśyas or even śūdras, may be accepted as a teacher if he has knowledge. Śrī Caitanya Mahāprabhu approved of this when He expressed this opinion before Rāmānanda Rāya ( Cc. Madhya 8.128):

kibā vipra, kibā nyāsī, śūdra kene naya yei kṛṣṇa-tattva-vettā, sei ‘guru’ haya

It does not matter whether one is a brāhmaṇa, śūdra, gṛhastha or sannyāsī. These are all material designations. A spiritually advanced person has nothing to do with such designations. Therefore, if one is advanced in the science of Kṛṣṇa consciousness, regardless of his position in human society, he may become a spiritual master.