In the scriptures it is stated: ṣaṭ-karma-nipuṇo vipro mantra-tantra-viśāradaḥ. A qualified brāhmaṇa must be expert in the occupational duties of a brāhmaṇa. His duties are mentioned as six brahminical engagements. Paṭhana means that a brāhmaṇa must be conversant with the Vedic scriptures. He must also be able to teach others to study the Vedic scriptures. This is pāṭhana. He must also be expert in worshiping different deities and in performing the Vedic rituals (yajana). On account of this yajana, the brāhmaṇa, being the head of society, performs all the Vedic rituals for kṣatriyas, vaiśyas, and śūdras. This is called yājana, assisting others in performing ceremonies. The remaining two items are dāna and pratigraha. The brāhmaṇa accepts all kinds of contributions (pratigraha) from his followers (namely, the kṣatriyas, vaiśyas and śūdras). But he does not keep all the money. He keeps only as much as required and gives the balance to others in charity (dāna).
In order for such a qualified brāhmaṇa to worship the Deity, he must be a Vaiṣṇava. Thus the Vaiṣṇava’s position is superior to that of the brāhmaṇa. This example given by Mādhavendra Purī confirms that even though a brāhmaṇa may be very expert, he cannot become a priest or servitor of the viṣṇu-mūrti unless he is initiated in vaiṣṇava-mantra.
Ref >> Srila Prabhupada Vani.