He looked just like an ordinary man, with
nothing remarkable about him. He used the most
simple language, and I thought, 'Can this man be
a great teacher ?'I crept near him and asked him
the question which I had been asking others all
my life: 'Do you believe in God, sir?' 'Yes.' `How
can you?' 'Because I see Him just as I see you
here, only in a much more intense sense.' That
impressed me at once. For the first time I found a
person who dared to say that he saw God, that
religion was a reality, to be felt, to be sensed in
an infinitely more intense way than we can sense
the world. I began to go to that man, day after
day, and I actually saw that religion could be
given. One touch, one glance, can change a
whole life.

said Swami Vivekananda about his guru Sri Ramakrishna. 

Born in the village of Kamarpukur in West Bengal on February 18, 1836 in a pious family, Sri Ramakrishna was very clear in his mind from boyhood that the aim of life is God-realization.

As a priest of the Kali temple at Dakshineswar he worshipped the Deity with such intensity that She revealed Herself to him and became his constant companion. He could talk, play and joke with Her. He then practiced not only the different spiritual streams of Hinduism, like Vaishnavism and Tantrism, but also other religions like Christianity and Islam. He was able to revalidate by his personal experience the Rig Vedic declaration, 'Truth is One, the wise speak of It variously.' He became the prophet of harmony of religions. 

Great scholars and savants sat at his feet and imbibed the grand spiritual truths he explained in an astonishingly simple way. The parables he narrated with scintillating humour are guidelines to all spiritual aspirants. He specially trained a band of young men who renounced the world, and after his passing away in August 16, 1886, formed the monastic Order, viz. Ramakrishna Math & Ramakrishna Mission.

Thanks to Chennai Math