Sanskrit Shlok on the importance of following the righteous path

अपन्थानं तु गच्छन्तम् सहोदरो अपि विमुञ्चति. 

Apanthaanam Tu Gachchhantam Sahodaro api Vimunchati. 

अर्थ: बुरे मार्ग पर चलने वाले का साथ उसका अपना सहोदर (भाई) भी छोड़ देता है. 

Meaning: If a person follows the wrong path, his own brother also leaves his side.