Mahabharata 3.32.8

3.32.8

vedādhyāyī dharmaparaḥ kule jāto yaśasvini |
sthavireṣu sa yoktavyo rājabhirdharmacāribhiḥ || 8 ||

The man of weak understanding who doubteth religion, virtue or the words of the Rishis, is precluded from regions of immortality and bliss, like Sudras from the Vedas! O intelligent one, if a child born of a good race studieth the Vedas and beareth himself virtuously, royal sages of virtuous behaviour regard him as an aged sage (not withstanding his years)! The sinful wretch, however, who doubteth religion and transgresseth the scriptures, is regarded as lower even than Sudras and robbers! Thou hast seen with thy own eyes the great ascetic Markandeya of immeasurable soul come to us! It is by virtue alone that he hath acquired immortality in the flesh. Vyasa, and Vasistha and Maitreya, and Narada and Lomasa, and Suka, and other Rishis have all, by virtue alone, become of pure soul! Thou beholdest them with thy own eyes as furnished with prowess of celestial asceticism, competent to curse or bless (with effect), and superior to the very gods! O sinless one, these all, equal to the celestials themselves, behold with their eyes what Is written in the Vedas, and describe virtue as the foremost duty! It behoveth thee not, therefore, O amiable Queen, to either doubt or censure God or act, with a foolish heart. The fool that doubteth religion and disregardeth virtue, proud of the proof derived from his own reasoning, regardeth not other proofs and holdeth the Rishis, who are capable of knowing the future as present as mad men.