The fool does not understand his own (True) Self; he pains others with his
speech. His underlying nature (of causing pain to others) does not leave
him; separated from the Lord, he suffers (sggs 549).

The Gur-Shabad indicates that it is the same One Consciousness that pervades everything in all of creation. To understand this Truth — also called Self Realization, God Realization, or Realization of our own True Nature, and so on — is indicated to be the ultimate purpose of the human life. In other words, the Realization of one's True Nature as the Universal Self ("Joti-Svaroopa), or to experience that one's True Self and God (or simply Truth) are one and the same.

  • ਸੋ ਬਉਰਾ ਜੋ ਆਪੁ ਨ ਪਛਾਨੈ ॥ ਆਪੁ ਪਛਾਨੈ ਤ ਏਕੈ ਜਾਨੈ ॥੪॥: So baouraa jo aap na pachaanai. Aap pacchaanai ta eko jaanai ||4||: Man is crazy without Self-realization. When he knows himself (ਆਪਣੇ ਅਸਲੇ ਦੀ ਪਛਾਣ, the Reality of his Being, his True Nature, etc.), only then he comes to know the One (All-pervading Truth). ||4|| (sggs 855).
  • ਜਨ ਨਾਨਕ ਬਿਨੁ ਆਪਾ ਚੀਨੈ ਮਿਟੈ ਨ ਭ੍ਰਮ ਕੀ ਕਾਈ ॥੨॥੧॥: Jan Nanak binu aapaa cheenai mitai n bhram kee kaaee ||2||1||: O Daas Nanak! Without Realizing one’s own self (Original, Essential, or True Nature, etc. – ਆਪਣਾ ਆਤਮਕ ਜੀਵਨ ਪਰਖਣ ਤੋਂ ਬਿਨਾ, etc.), the moss of doubt (ignorance of one’s True Nature, etc.) is not eradicated (from the mind) ||2||1|| (sggs 684). 
  • ਇਉ ਕਹੈ ਨਾਨਕੁ ਮਨ ਤੂੰ ਜੋਤਿ ਸਰੂਪੁ ਹੈ ਅਪਣਾ ਮੂਲੁ ਪਛਾਣੁ ॥੫॥: Iou kahai Nanaku man toon joti saroopu hai apanaa moolu pashaanu ||5||: Thus says Nanak - O mind! Your "Saroop" (your own, True State) is "Joti" (Divine Light)! Recognize your Mool (Source, Origin, Reality...) ||5|| (sggs 441).

However, in reality, it's the opposite that happens in lives of the most of us (over 99.9 percent category). That is, we try to understand everything and everybody else but ourselves. The well known material scientist Albert Einstein in his final days is attributed to saying that, "Sometimes I suspect that my life has been a waste. I inquired into the farthest of stars and forgot completely to inquire into myself—and I was the closest star!"

Even in the case of those who claim themselves to be highly educated, cultured, wise and versed in scriptures, nothing could be farther from the truth. It is because, due to the rise of the false ego-sense within (Haume or relativist consciousness), our present perception of the Reality is only relative and limited — far away from the Absolute Truth.

As time and again indicated in the Gurbani, scholarly debates on debating the Truth is not encouraged. Because those who call themselves scholars and debate the Truth don't necessarily know the Truth themselves! As indicated in the SGGS, the problem with the most of us is that we are trying to understand everybody and everything but our own True Self. We are strongly urged by the Gurbani (Sri Guru Granth Sahib, SGGS) to renounce such ways. Instead, we are challenged by the Gurbani to look within to examine and understand ourselves. If we dare doing what the Gurbani asks us to do here, then and only then we will be known as "real judge".

  • ਨਾਨਕ ਪਰਖੇ ਆਪ ਕਉ ਤਾ ਪਾਰਖੁ ਜਾਣੁ ॥: Nanak parkhe aap kayu ta paarakh jaan: O Nanak, if someone judges himself, only then is he known as a real judge (sggs 148).
  • ਆਪਣਾ ਆਪੁ ਨ ਪਛਾਣੈ ਮੂੜਾ ਅਵਰਾ ਆਖਿ ਦੁਖਾਏ ॥ ਮੁੰਢੈ ਦੀ ਖਸਲਤਿ ਨ ਗਈਆ ਅੰਧੇ ਵਿਛੁੜਿ ਚੋਟਾ ਖਾਏ ॥: Apnaa aap na pashaanai mooraa avraa aakh dukhaaye ..: The fool does not understand his own (True) Self; he pains others with his speech. His underlying nature (of causing pain to others) does not leave him; separated from the Lord, he suffers (sggs 549).

The SGGS says that our minds become Pure only when we realized our True Self ("Joti-Svaroopa) within. In other words, to gain True Understanding, complete Realization of the True Self within is must. Otherwise there can be no True Understanding of God or Purity of the mind.

  • ਆਪੁ ਪਛਾਣੈ ਬੂਝੈ ਸੋਇ ॥: Aap pashaanai boojhai soi: He who recognizes his Self comprehends God (sggs 57).
  • ਜਿਨਿ ਆਤਮ ਤਤੁ ਨ ਚੀਨ੍‍ਆਿ॥ਸਭ ਫੋਕਟ ਧਰਮ ਅਬੀਨਿਆ ॥: Jin aatam tat na cheeniyaa; Sabh fokat dharma abeeniyaa: Whoever does not gain the knowledge of the Self, all his religious acts are vain and blind (sggs 1351).
  • ਨਾਨਕ ਚੀਨੈ ਆਪ ਕਉ ਸੋ ਅਪਰ ਅਪਾਰਾ ॥੮॥: Nanak cheenai aap kayu so apar apaaraa: O Nanak, one who knows his real Self (ਆਪਣੇ ਅਸਲੇ ਨੂੰ ਪਛਾਣ ਲੈਂਣਾਂ, ਆਪਾ ਪਛਾਣਨ ਦਾ ਆਤਮਕ ਦਰਜਾ, etc.), becomes Infinite and Incomparable (i.e., he becomes God-like) ||8|| (sggs 229).

Now, the question is: why the majority of us don't understand our True Self? The SGGS dissects our minds and tells us exactly what the problem is — "Filled with ignorance (the delusion of the tripple-qualitied Maya); one does not understand himself." In other words, when in doubts or Manmukh-consciousness (Haume or materiality: lust, anger, greed...), we cannot understand the essence of the Reality.

  • ਅੰਤਰਿ ਤਾਮਸੁ ਆਪੁ ਨ ਪਛਾਣੈ ॥: Antar taamas aap na pashaanai: Filled with darkness (ignorance); one does not understand himself (sggs 231).
  • ਤਤੁ ਨ ਚੀਨੈ ਮਨਮੁਖੁ ਜਲਿ ਜਾਇ ॥ ਦੁਰਮਤਿ ਵਿਛੁੜਿ ਚੋਟਾ ਖਾਇ ॥ ਮਾਨੈ ਹੁਕਮੁ ਸਭੇ ਗੁਣ ਗਿਆਨ ॥: Tatu n cheenai manmukhu jali jaai. Durmati vichhurri chotaa khaai. Maanai hukamu sabhe gun giaan: The Manmukh (self-willed, ਮਨ ਦੇ ਪਿੱਛੇ ਤੁਰਨ ਵਾਲਾ ਮਨੁੱਖ, etc., who) does not understand the Essence (ਤਤ ਵਸਤੂ, ਤਤ ਗਿਆਨ, Essence of Realiy-ਅਸਲੀਅਤ- or Divine Knowledge that is contained in the Gurbani), burns (in Maya, evil passion-ਵਿਕਾਰਾਂ ਵਿਚ...). (Because of his) evil-mindedness, (he remains) separated from (his Mool, Truth...) and suffers. (One who) accepts the Divine Hukam, he is blessed with all Divine Virtues and total Spiritual Wisdom. (sggs 944).
  • ਭਰਮਿ ਭੁਲਾਣਾ ਸਬਦੁ ਨ ਚੀਨੈ ਜੂਐ ਬਾਜੀ ਹਾਰੀ ॥: Bharam bhulaanaa sabad na cheenai jooai baajee haaree: Deluded by doubt, one does not remember the Shabad; thus gambles his life away (sggs 1012).

The True Self is beyond the body-mind-intellect apparatus and hence is not affected by the afflictions that beset these human faculties. The SGGS reiterates this fact so that a spiritual seeker will come to terms with the ephemeral nature of the human personality and identify with the True Self instead ("Joti-Svaroopa"), which is Eternal or Infinite in Nature.

But it is easier said than done as can be seen in practice when a person embarks on the spiritual path (which is mentioned in the SGGS to be a "two-edged sword"). As indicated in the SGGS, to understand our True Self, we need the Guru's Grace and need to become Gurmukhs (spiritual being), leading a Divine Life. The following verses and many more throughout the SGGS provide us with pointers as to how we can understand our True Self.

  • ਗੁਰ ਕੈ ਸਬਦੇ ਆਪੁ ਪਛਾਣੈ ॥: Gur kai sabade aap pashaanai: Through the Guru's Shabad, he realizes his (True) Self (sggs 224).
  • ਗੁਰਮਤੀ ਆਪੈ ਆਪੁ ਪਛਾਣੈ ਤਾ ਨਿਜ ਘਰਿ ਵਾਸਾ ਪਾਵੈ ॥: Guramatee aapai aap pashaanai taa nij ghar vaasaa paavai: Under Guru's Instruction, one comes to understand his (True) Self, and then, he comes to dwell in the Home of his inner Self (sggs 565).
  • ਨਾਨਕ ਤਾ ਕਉ ਮਿਲੈ ਵਡਾਈ ਆਪੁ ਪਛਾਣੈ ਸਰਬ ਜੀਆ ॥: Naanak taa ko milai vadaaee aap pashaanai sarab jeeaa: O Nanak, he is blessed with glorious greatness; he realizes his (True) Self and sees (himself) in all beings -- he sees the same Light in all beings which resides in him (sggs 940).
  • ਆਪੁ ਪਛਾਣੈ ਸੋਈ ਜਨੁ ਨਿਰਮਲੁ ਬਾਣੀ ਸਬਦੁ ਸੁਣਾਇਦਾ ॥: Aap pashaanai soee jan niramal bani sabad sunaaidaa: That humble being who (through the Gur-Shabad) understands his (True) Self becomes immaculate (free of Bikaars). And he preaches the Guru's Bani/Shabad to others (sggs 1065).
  • ਆਪੁ ਪਛਾਣੈ ਘਰਿ ਵਸੈ ਹਉਮੈ ਤ੍ਰਿਸਨਾ ਜਾਇ ॥: Aap pashaanai ghar vasai houmai thrisanaa jaai: Through realizing the (True) Self, people dwell within the Home of their inner being and their ego and desire depart (sggs 57).
  • ਗੁਣ ਸੰਗ੍ਰਹਿ ਅਵਗਣ ਵਿਕਣਹਿ ਆਪੈ ਆਪੁ ਪਛਾਣੈ ॥: Gun sangrahi avagan vikanahi aapai aap pashaanai: He (the Gurmukh) gathers in merits, and eliminates demerits, and realizes his (True) Self (sggs 568).
  • ਨਾਨਕ ਆਪੈ ਆਪੁ ਪਛਾਣੈ ਗੁਰਮੁਖਿ ਤਤੁ ਬੀਚਾਰੀ ॥: Nanak aapai aap pashaanai gurmukh tata beechaaree: O Nanak, by becoming the Gurmukh, realize your (True) Self and reflect on the essence of Rfeality (sggs 1112).
  • ਆਪੁ ਪਛਾਣੈ ਹਰਿ ਮਿਲੈ ਬਹੁੜਿ ਨ ਮਰਣਾ ਹੋਇ ॥: Aap pashaanai har milai bahurr na maranaa hoi: One who understands his (True) Self, meets with the Lord, and never dies again (sggs 1410).
  • ਚੀਨੈ ਆਪੁ ਪਛਾਣੈ ਸੋਈ ਜੋਤੀ ਜੋਤਿ ਮਿਲਾਈ ਹੇ॥: Cheenai aap pashaanai soee jotee joti milaaee hay: One who understands his (True) Self, realizes the Lord, and his light blends with thw Supreme Light (sggs 1024).
  • ਐਥੈ ਬੂਝੈ ਸੁ ਆਪੁ ਪਛਾਣੈ ਹਰਿ ਪ੍ਰਭੁ ਹੈ ਤਿਸੁ ਕੇਰਾ ॥: Aithai boojhai su aap pashaanai har prabh hai tis keraa: One who understands here and realizes his (True) Self; God belongs to him (sggs 602).

— T. Singh