Vaishnava Samhita. Gopinatha Charitam. Vol II Book VI Chp 6 Shlokas 11 - 14

निरपेक्षं महाशान्तं सर्वशास्त्रार्थवित्तमम्  |
सर्वसद्गुणसंपूर्णं ज्ञानवैराग्यभूषणम्  ||   
कृष्णभक्ताग्रगण्यञ्च कृष्ण भक्ति प्रदायकम्  |
दृढनिष्ठं स्वधर्मे च वैदिकाचारसम्युतम्   |
पाषण्डखण्डनं धीरं पण्डितैः परिपूजितम्   ||   
लोकवेदविनिर्मुक्तं भगवद्ध्यानतत्परम् |
निर्योगक्षेमपरमं निर्भयं निर्भरं तथा  || 
एवं बहुगुणैर्युक्तमाचार्यं कुशलो नरः  |
आश्रित्य भगवद्बुद्ध्या कुर्यात् सेवामहर्निशम्  || 

A wise man should take as the god incarnate a guru who is detached, equanimous, adept in all shastras, endowed with all noble qualities, adorned with wisdom and a withdrawn attitude, a great devotee of Lord Krishna, capable of imparting Krishna bhakti, very keen in following swadharma, following the Vedas, courageously condemning the pseudo religious, brave standing above the Vedic and earthly bonds, having Krishna dhyana as the only object, never caring for the welfare of the self and not burdened by fears or cares. He should take refuge in such a guru and serve him day in and day-out.