Words like Guru, Acharya and Upadyaya were carefully used in the ancient India. These words are very much related to the imparting of knowledge, yet they have differences in meaning. Acharya is greater than Upadyaya. But the Guru is greater than the Acharya. In the Vedas the voice of the Acharya is very common. In the modern Mundakopanisheth and Swethaaswathoupanisheth one can find Guru sabtha. The Guru sabtha became prominent during the time of Upanisheth when the importance was transferred from sacrifice (during the Vedic period) to gnana.  The Adwaidarakopanisheth explains the Guru as follows

“Gusabtha stwanthakara syath

Ru sabthasthannirodhaka

Anthakara Nirodhithwath

Gururithyabheethiyathe”

Gu means darkness and Ru means blocking it. So Guru is one who dispels darkness.

Adwaidarakopanisheth continuous as follows:

“Gurureva Parambrahma

Gurureva Paramgathi

Gurureva Pramvidya

Gurureva Parayanam

Gurureva Parakashta

Gurureva Paradhanam

Yasmath Thapadeshttasou

Thasmad Gurutharo Guru Ithi”

Guru is Parabrahma (God). Guru is the ultimate solace, he is the ultimate wisdom and worthy of praise. Guru is greatest among the great. If one pronounces his name, he will receive the gift of freedom from samsarasagara. All sins will go away. He will receive objects of life (Dharma, Artha, Kama, Moksha) One who realizes all these things is upanisheth gnani.

The Bible uses the word Guru almost fifty times. Three Hebrew words are translated as Guru in the Old Testament. Ab = Father (1 Sam. 10:12), Meveen = Wiseman (1 Chro. 25:8), Mlamdeem = Teacher (Ps. 119:99). The New Testament uses the word didaskalos. This word as noun has emerged out of the root Didasko which means to teach. Jesus also calls himself Guru in the Gospels (Matt. 8:19; 12:38; 19:16; 22:16, 24, 36; Mk. 4:38; 9:17,38; 10: 17, 20, 35; 12: 14, 19,32). The addressing as Guru is found in great frequency in the Gospel of Luke. Both, Rabi (Jn. 1:38) and Rabuni (Jn. 20:16) mean guru only. Jesus introduced himself as Guru and Lord (Jn. 13:11). Greatness is the quality of Guru. 

1. Solomon: The learned Teacher (Pro. 4:1-19)

The Bible depicts Solomon as a wise man. But he says it is his parents who have taught him wisdom (Pro. 4:3-19). Solomon has advised to listen to the parents and stick to their advice to attain true wisdom. Guru – Sishya relationship should start at home. Parents are our first teachers. Children start learning from the parents. The parents should keep this truth in mind (Eph. 6:1-4). 

2. Paul: A learned Teacher (Acts 22:1-5)

Paul started his primary education in a Jewish school. He has used the Greek Old Testament (LXX). At the age of 12, as per the Jewish custom at the end of the childhood education, he has been declared ‘son of the law’. He took higher education under Gamaliel. Gamaliel was a Jew, an Old Testament scholar and a man of religious tolerance (Acts 5:30-35). It is believed that Paul would have stayed at Jerusalem after the age of 12 and continued his education (Acts 22:3). This training under Gamaliel lasted for four to five years. This education inspired him to become the Christian interpreter of the Old Testament later in his years. He would have spent time to listen to the talks of the learned men at Tarsus. The major topics were stoic philosophy and Greek literature (Acts 17:28; 1 Cor. 15:33; Timo. 1:12). But apart from these subjects (Homer, Plato) the law and the prophets were his prominent subjects.  

3. Jesus: The Best Teacher (Lk. 4:31-44)

Jesus said to his disciples, “I am teacher and Lord” (Jn. 13:13). Jesus has not only admonished, preached and taught but also practiced what he preached. He also called the people to listen to his teachings and do accordingly. Jesus the Guru told his followers as follows: “To the Jews who had believed him, Jesus said, “If you hold to my teaching, you are really my disciples” (Jn. 8:31). As Jesus was almost finishing his earthly ministry he told his apostles: “Therefore, go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age” (Matt. 28:19-20). The Guru has demanded to teach what he has taught rather than preaching about the Guru himself.