Here are some great sanskrit hymns from ancient Indian texts..
Nahi Jnanena Sadrsham
Nothing is equivalent to knowledge

Vasudaiva Kutumbakam
The whole earth is a family

Satyameva Jayate
Truth always triumphs

Dharmo Rakshathi Rakshithaha
He who carries out his duties shall be protected

Sarvejana Sukhinobhavanthu
May all the people in this universe live with happiness and prosperity

Janma Jaata Shudra Sarve
Karmenu Brahman Bhavati
All humans are inferior (Shudra) by birth and they become superior (Brahmins) only by their good deeds later in their life.

Asatho Ma Sathgamaya,
Thamaso Ma Jyothirgamaya
Mruthyorma Amrthangamya

Lead me towards truth from untruth
Lead me towards light from darkness
Lead me towards immortality from Death

Yatra Naaryasthu poojyanthe
Ramanethe thatra devathaha

Where women are treated with dignity and Womanhood is worshipped, there Roam the GODS

Ekam Sat Vipraha bahudha vadanti
There is but one God, learned scholars call this God by different names

Isha vasya midam sarvam
The entire universe is pervaded by God

Sarve amritasya putrah
We are all the children of God

Ati Vinayam Dhoortha Lakshanam
Too much of humbleness is an attribute of a wicked person

Aham Brahmasmi
I am God (indicating God lives inside humans)

Lobhaha Papasya Karanam
Greed is the root cause of sin

Matru Devo Bhava Pitru Devo Bhava
Acharya Devo Bhava Athithi Devo Bhava
Treat your Mother, Father, Teacher and Guest like a God

Satyam bruyat priyam bruyat na bruyat satyam apriyam
priyam cha nanrutam bruyat esha dharmah sanatanah
Only speak the truth that is pleasant to others
Do no speak the truth that might be unpleasant to others
Never speak untruth that is pleasant to others
This is the path of the eternal morality called Sanatana Dharma

Annam na nindhyath
Annam na pari-chaksheeta
Annam bahu kurveeta
Do not abuse food
Do not discard food
Grow food in abundance!

shubham karoti kalyaaNam aarogyam dhanasampadaa
shatrubuddhi vinaashaaya deepajyoti namostute
I salute the light from the lamp, the one that brings auspiciousness, prosperity, good health, abundance of wealth, and the destruction of the intellect’s enemy!
(said while lighting the evening lamp)

Kaalaaya Tasmai NamahaSalutations to that great entity called TIME
Satyam Vadha Dharmam CharaSpeak the truth, follow the righteous path
Aa no bhadrah kratavo yantu vishwatahMay auspicious thoughts come to us from all over the world.
Mata Bhumih putro ham prithvyahEarth is our mother and we are its children.