By means of great mercy G-d created the most divine and the utter sublime. G-d shines His light into the souls of Israel and in the reflection of His light we experience and understand Him in everyway conceivable [this is the greatest gift, for anything else is secondary]. G-d does this with infinite wisdom granting free choice to the recipients of His goodness to determine that it is in fact G-d's light they are experiencing that is sustaining them. Based on the position of your soul you testify and acclaim G-d.
There is a Master of all the souls, this is the Tzadik (righteous one), the Ambassador of G-d (so to speak). Thus our relationship with G-d and our every experience is completely pivoted on the Tzadik. The Tzadik is responsible for building the Kingdom of f G-d in the light of G-d as it reflects from all the souls of Israel. The Tzadik guides and uplifts all creation. An individual soul or group of souls can not pay tribute to G-d without acknowledging His Tzadik. We must follow the ways of the Tzadik. When we pay homage to the Tzadik we honor G-d. That is the way G-d chose to create the world for our benefit.
Rabbi Nachman of Breslov lived approximately 200 years ago. Rabbi Nachman was born in the house of his great grandfather the Baal Shem Tov (father of Chasidism). Aside from the purity and holiness of his soul which enabled him to special perception of the divine, his genius allowed him to learn a book by just perusing it in a few moments. Despite these gifts, Rabbi Nachman did not choose to spend his time and energy in kabalistic meditation nor the pursuit of wisdom, rather he desired to seek G-d in the most simple and meaningful fashion. He was particularly fired by stories of devotion of the early Chasidim. At a very young age Rabbi Nachman purged his body of all desire, subjugating it to the holy desires of his soul. He delighted in doing abundant common mitzvot. Most important, Rabbi Nachman mastered the prime service of G-d, Prayer, especially Hisbodidus ['to be alone with G-d', that is to speak to G-d personally, in your own words, knowing that He is paying great attention]. Rabbi Nachman teaches that everything that there is to achieve can be achieved through prayer (more over anything that was achieved without prayer, is lacking). Many Rabbis had previously taught the importance of prayer, Rabbi Nachman established and instilled the ways of prayer in the world. Just as we have now 4 established prayers (shacharis, mincha, mariv, tikun chatzos) when Moshiach comes everyone will be praying a 5th prayer, in his own words, known as Hisbodidus, as established by Rabbi Nachman. Fortunate are those who begin this practice now.
As a result of his great self sacrifice and devotion to G-d, Rabbi Nachman became the Master of all the souls of Israel. Rabbi Nachman saw every soul, from Adam till the coming of the Moshiach, and every rectification necessary for every soul, and he addresses each and everyone, without exception, in the holy books which he authored.
Anyone who desires to have mercy on himself should study and practice Rabbi Nachman's teachings. The rectification of the world and the final redemption are completely reliant on this.
Some other teachings of Rabbi Nachman: 'There is no despair in the world whatsoever!'; 'depression and sadness are the tools of the evil side. It is a great mitzva to be happy – always!'
In 1922, Rabbi Yisroel Dov Odesser zt"l, known as the Saba, received a Petek (note) from Rabbi Nachman: Very hard it was for me to descend to you\ my precious student to tell you that I enjoyed\ greatly your service and upon you I said\ my fire will burn until the\ mashiach will come be strong and courageous\ in your service\ Na Nach Nachmu Nachmun MayUman\ and with this I shall reveal to you a secret and it is\ full and heaped up from end to end (PTzPTzYH)\ and with strong service you will understand it and a sign\ the 17th of Tamuz they will say that you are not fasting. Rabbi Nachman signed his name in this unique fashion! Also, R' Yisroel's name is not mentioned, it is for one and all.
60 years later the Saba began to publicize the Petek. Saba said: 'If I were to reveal just two words about the Petek, I would annul the free will of the whole world.', 'This is a novelty and wonder, the likes of which have never before been seen in this world. The song Na Nach Nachmu Nachmun MayUman fixes everything and heals everything!', 'This is only from Rabainu, only a miracle. A signature such as this' no Tzadik ever signed a signature like this: the "simple, doubled, tripled, quadrupled." And Rabainu in his lifetime also never signed this way. Only in this Petek – we didn't know – this is found in Likutay Moharan, that the holy Rabainu talks about this Song. He is this Song. But here, he reveals to all the world Na Nach Nachmu Nachmun MayUman. What is now in the world, was never known, we know nothing.' Saba inspired R' Moshe Feinstein zt"l with it, and received from R' Moshe a letter of recommendation so testifying.
Saba said: 'Na Nach Nachmu Nachmun MayUman is a segula (object or saying with saving powers) for every problem and situation.' 'This song is the matter of the redemption.' 'Na Nach Nachmu Nachmun MayUman lifts man from absolute descent to absolute ascent.', 'Just to say this name Na Nach Nachmu Nachmun MayUman, sweetens all the sufferings and all the judgments, all the sins and all the blasphemy – everything! It transforms everything, happy is the one who believes.', 'We have no conception what it is, that we merited, in these generations, to know from this, from a secret like this Na Nach Nachmu Nachmun MayUman. There is a great deal to speak about, but I can not speak!'