Some saints left their mark on humanity through their accomplishments, others through their worship practices and sacrifice.
As for Shirdi Sai Baba, His greatness revealed itself in His every day life, through the demonstration of ideal (dharmic) actions. Put simply, the way He conducted His life, and the teachings expressed through His exemplary actions, was His greatness.
He taught the fundamentals of Advaita Vedanta (philosophy of non-duality) and Sanatana Dharma (ideal behavior) by living with the common man, demonstrating endless compassion toward all living beings, and shaping each and every person who was blessed to get His darshan.
Today, Shirdi Sai Baba still influences humanity, as devotees from all around the world flock to His temples, study His life, and apply His teachings.
The word “Sai” is actually a Farsi term used for Sufi or Parsi sadhus, which means, “Poor One,” a “Fakir,” a wandering mendicant.
In Sanskrit, it means “Actual” or “True.” The word “Baba” means Holy Father, and Shirdi is a geographical location in the Indian State of Maharashtra, where Sai Baba lived.
So, this revered Saint, Shirdi Sai Baba, is known as a True Holy Father who resided in Shirdi.
He exhibited all the qualities of a Divine Father – compassion, charitable giving, teaching by example, and mastery of the scriptures. In so doing, He set a perfect path for spiritual aspirants to move closer to union with God.
Shirdi Sai Baba’s Universal Teachings and Practices combined elements of Hinduism, Islam, and Zoroastrianism. In fact, He practiced rituals from all religions. 
He encouraged everyone to chant God’s name and to read the holy scriptures.To Muslims, they were to study the Qur’an. To Hindus, they were to study Hindu texts like the Ramayana, the Bhagavad Gita, and Yoga Vasistha.
He interpreted these religious texts and explained the meaning of them in the spirit of Advaita Vedanta. His philosophy also had numerous elements of bhakti (devotion).
Teaching the universal nature of all religions, He paved the way for Muslims and Hindus to forge open relationships, saying:
“Sab ka Malik ek!”
“There is but One God!”
Thoughtful Reflections from Shree Maa & Swamiji
From Shirdi Sai Baba, I was most impressed by the teachings of Shraddha – Faith, and Saburi – Patience, and I made those two the cornerstones of my sadhana.
Even to this day, when, as an elderly man I feel aches and pains in chanting while sitting in an asana, I counsel patience; because I have Faith that I am engaged in a noble enterprise.
How fortunate I was to have an example and Friend like Shirdi Sai Baba!
~ Swamiji
Shirdi Sai Baba was especially impressed by the philosophy of the Bhagavad Gita and encouraged people to follow its message in their own lives.
For example, He emphasized the importance of performing one’s duties without attachment to earthly matters and of being content regardless of the situation.
In terms of spiritual qualities, He declared that there are two important features of character:
1) Shraddha – Faith, unflinching perseverance in the face of all obstacles
2) Saburi – Patience, waiting with patience and love for the right time for any action to come to fruition.
Shirdi Sai Baba’s Compassion and Charitable Giving served as the blueprint of His life and became essential to His teachings.
He encouraged charity and stressed the importance of sharing. He urged His devotees and followers to lead a moral life, to help others, and to love every living being without any discrimination.
Through His own actions, he demonstrated how this could be done and showed that it was within the reach of the common man to demonstrate this level of compassion.
For example, He often treated the sick and injured. He prepared food for His visitors, especially the poor. In His presence, all castes sat together on the ground. No one had an elevated position.
He advised: “Unless there is some relationship or connection, nobody goes anywhere. Therefore, if any men or creatures come to you, do not discourteously drive them away, but receive them well and treat them with due respect.
Shri Hari (God) will certainly be pleased if you give water to the thirsty, bread to the hungry, clothes to the naked, and your verandah to strangers for sitting and resting. If anybody wants any money from you, and you are not inclined to give, do not give, but do not bark at him or her like a dog.”
This compassionate message was not just communicated orally; Shirdi Sai Baba demonstrated it through His every action.