Sankaracarya's Vivekachudamani 475

समाधिना साधुविनिश्चलात्मना

पश्यात्मतत्त्वं स्फुटबोधचक्षुषा ।

निःसंशयं सम्यगवेक्षितश्चेच्

छ्रुतः पदार्थो न पुनर्विकल्प्यते ॥

samādhinā sādhuviniścalātmanā

paśyātmatattvaṃ sphuṭabodhacakṣuṣā |

niḥsaṃśayaṃ samyagavekṣitaścec

chrutaḥ padārtho na punarvikalpyate |

(Sankaracarya's Vivekachudamani 475)

Perceive the nature of the Self with the eye of perfect Knowledge through Samadhi, where the mind has been brought to complete quietude. If the declarations of Sruti (heard from the Teacher) are perfectly understood without a trace of doubt, it can lead to no more skepticism.

One has to understand the nature of the soul and Supreme Lord with perfect eyes or intelligence. It's like accepting knowledge in a very humble way. One should not doubt the knowledge of Vedas.

is it stated in Śrī Īśopaniṣad

oṁ pūrṇam adaḥ pūrṇam idaṁ

pūrṇāt pūrṇam udacyate

pūrṇasya pūrṇam ādāya

pūrṇam evāvaśiṣyate

The Personality of Godhead is perfect and complete. And because He is completely perfect, all emanations from Him, such as this phenomenal world, are perfectly equipped as a complete whole. Whatever is produced of the Complete Whole is also complete by itself. And because He is the Complete Whole, even though so many complete units emanate from Him, He remains a complete balance.

So whatever comes from the Lord, there is no question of doubt and skepticism. Further, the slokas of Vedas if hear through a bonafide *Spiritual master(guru) or pure devotee, it add more confidence. One should give doubting our Vedas and dharma.

The bonafide spiritual master is someone who is 24/7 thinking about the Lord, He never likes to have many followers, he never like to have comfort and money. His only thoughts about the Lord and read about him.