A true friend is the best possession

जाड्यं धियो हरति सिञ्चति वाचि सत्यम्
मानोन्नतिं दिशति पापमपाकरोति ।
चेतः प्रसादयति दिक्षु तनोति कीर्तिम्
सत्सङ्गतिः कथय किं न करोति पुंसाम् ॥

- नीतिशतकम्

It removes inertia of the mind, fosters truthfulness in words, leads to enhancement of dignity and prestige, expiates sins, pleases the mind and pervades fame in all directions. Is there anything that the company of virtuous people doesn't achieve?

A true friend is the best possession.
A man is known by the company he keeps.
Keep good company and you'll be counted one of them.