For a person, there are two ways to grow in life — either to grow up or to grow old. Growing up is to become a Gianee or spiritually Wise. Growing old is to live in bondage and let the body just wither away only to meet the painful death at the end of the life's journey. Thus, to grow up spiritually is immateriality: that which is not material. It's Divine or Holy. In other words, growing up is to mend our ways and thus bring about a shift in our perception — from worldly to the spiritual, from the external to the internal, and so on.

Growing up is synonymous with becoming the Gurmukh. To the contrary, growing old and die like a worm in the end is synonymous with the term Manmukh used in the Gurbani (Sri Guru Granth Sahib, SGGS). As indicated in the Gurbani, the Gurmukh never grows old; for he possesses intuitive understanding and spiritual wisdom. The Manmukh, on the other hand, is exactly the opposite of the Gurmukh.

• gurmuiK buFy kdy nwhI ijn@w AMqir suriq igAwnu: Gurmukh budhe kade naahee jinhaa antar surat giaan: The Gurmukhs never grow old; within them is intuitive understanding (of the real purpose of life) and spiritual wisdom (sggs 1418).

• gurmuiK igAwnu ibbyk buiD hoie: Gurmukh giaan bibek budh hoi: The Gurmukh is blessed with spiritual wisdom and a discerning intellect (sggs 317).

• cwry kuMfw Biv Qky mnmuK bUJ n pwie: Chaare kundaa bhav thakke Manmukh boojh na paai: The Manmukhs (self-willed materialists or Mayadhaaree) grow weary of wandering around in all four directions (i.e., deteriorate or abate their spiritual life or Aatmic Jeevan), but they do not understand (the real purpose of life) (sggs 37).

• hir pRB kw sBu Kyqu hY hir Awip ikrswxI lwieAw ]gurmuiK bKis jmweIAnu mnmuKI mUlu gvwieAw: Har prabh kaa sabh khet hai har aap kirasaanee laaiaa. Gurmukh bakhas jamaaeean Manamukhee mool gavaaiaa: Everyone (the entire world) is (like) the field of the Lord; the Lord has engaged (Jeevas) in cultivating this field (i.e, He sends Jeeva for Naam-Simran). Those who have become the Gurmukhs, the Lord mercifully grows their crop, while the Manmukhs even lose their capital (i.e, lose their human birth) (sggs 304).
• mnmuK mrih AhMkwir mrxu ivgwiVAw: Manmukh marahi ahankaar maran vigaarriaa: The Manmukhs die in egotism, even their death is painfully ugly (sggs 86).

Apparently, in the state of Manmukhtaa, we tend to follow the dictates of our mind (Haume or false ego-sense: lust, anger, greed, etc.), which are motivated only by our selfish likes and dislikes. Conversely, in the state of Gurmukhtaa, we lead life wisely (Divine Life). Therefore, the Gurbani time and again urges us not to follow the human nature that likes to relegate the pursuit of the spiritual goal — becoming the Gurmukh while living in the body — for attaining liberation from repeated suffering to old age. Because, first, there is no guarantee that one's life will follow a structured course wherein one will find the time and energy to execute the goals one has set for oneself or about one's lifespan. Second, a layperson cannot decide what is the right age for this.

• nwnk musY igAwn ivhUxI Kwie gieAw jmkwlu: Nanak musai giaan vihoonee khaaye gaiaa jamakaal: O Nanak, without divine knowledge, one is plundered, and devoured by death (sggs 465).
• mnmuK kwlu ivAwpdw moih mwieAw lwgy: Manmukh kaal viaapadaa mohi Maya laage: The Manmukhs are afflicted by death; they cling to Maya in emotional attachment (sggs 1090).
• igAwnI hovY su gurmuiK bUJY swcI isPiq slwhw hy: Giaanee hovai su gurmukh boojhai saachee sifati salaahaa hae: One who is Spiritually Wise, understands himself by becoming a Gurmukh; he praises the True One (sggs 1056).
• gurmuiK igAwnu qqu bIcwrw joqI joiq imlwey: Gurmukh giaan tat beechaaraa joti jot milaaye: The Gurmukh, spiritually wise, engages in Vichaar or inquiry of the essence of spiritual wisdom; his individual light merges into the Supreme Light (sggs 1131).
• gurmuiK hovY so mukqu khIAY mnmuK bMD ivcwry: Gurmukh hovai so mukat kaheeai manmukh bandh vichaare: One who becomes Spiritual being (Gurmukh) is said to be liberated, while the poor materialists (Manmukhs) are in bondage (sggs 796).
• gurmuiK cwnxu jwxIAY mnmuiK mugDu gubwru: Gguramukh chaanan jaaneeai Manmukh mugadh gubaar: The Gurmukh knows the Divine Light, while the foolish Manmukh gropes around in the darkness (sggs 20).
• mnmuK mUV mwieAw icq vwsu: Manmukh moorr Maya chit vaas: The consciousness of the foolish, Manmukh is the dwelling place of Maya (sggs 222).
• haumY pcY mnmuK mUrwKw: Houmai pachai manmukh mooraakhaa: The foolish Manmukhs are consumed by their egotism or Haume (sggs 394).
• mnmuiK BUly siB mrih gvwr: Manmukh bhoole sabh marahi gavaar: The foolish Manmukhs all go astray and die (sggs 665).
• jb lgu jrw rogu nhI AwieAw]jb lgu kwil gRsI nhI kwieAw]jb lgu ibkl BeI nhI bwnI]Bij lyih ry mn swirgpwnI ]2]Ab n Bjis Bjis kb BweI]AwvY AMqu n BijAw jweI]jo ikCu krih soeI Ab swru]iPir pCuqwhu n pwvhu pwru: Jabb lagu jaraa rogu nahee aaiaa. Jabb lagu kaal grasee nahee kaaiaa. Jabb Lagu bikal bhaee nahee baanee. Bhaji lehi re mann saarigapaanee. ||2|| Ab na bhajasi bhajasi kab bhaaee. Aavai antu na bhajiaa jaaee. Jo kish karahi soee ab saaru. Firi pashutaahu na paavahu paar: As long as the disease of old age has not come to the body, and as long as death has not come and seized the body, and as long as your voice has not lost its power, O mortal being, meditate on the Divine ||2|| If you do not meditate on Him now, when will you, O brother? When the end comes, you will not be able to meditate on Him. Whatever you have to do - now is the best time to do it. Otherwise, you will regret and repent afterwards, and you will not be carried across to the other side (sggs 1159).
  

The true Gurmukhs and the rest of us (Manmukhs) live in the same world. However, the Gurmukh sees the world as it is, while the rest of us don't. For example, we see ourselves in the world, while the Gurmukh sees the world in himself; for everything exists in the Infinite Consciousness. Consequently, to us, we take birth and die; while to him it is the world that appears and disappears in the mind! The Gurmukh thus is a Timeless Being, and there is no birth or death in the state of timelessness. He realizes his own unassailable Nature (Joti-Svaroopa). People are afraid of death. However, the true Gurmukh is afraid of nothing; for he is fearless. It is natural for the Self or the Self-realized being to be fearless, but to be afraid of death or anything is not. Only the body-conscious person (Manmukh) is afraid of death. Since the Giaanee or the Gurmukh knows he is neither the body nor the mind, thus the event of death has no effect on him. He is the Changeless Reality, beyond time and space; thus Immortal and untouched by the death. The Gurmukh knows that what comes and goes is unreal. That which is Real never dies, and that which dies is not Real. Since the Gurmukh's mind is already dead, he has no reaction to death. For him it's natural for the body to die, as it is natural for the incense stick to burn out. He sees body and Soul as two separate entities — the body bound in time and space that comes and goes, whereas the Soul is eternal, free of birth and death.

• gurmuiK jmkwlu nyiV n AwvY ]haumY dUjw sbid jlwvY]nwmy rwqy hir gux gwvY: Gurmukh jamkaa nerhi na aavai. Haumai doojaa shabadi jalaae: The Messenger of Death does not even approach the Gurmukhs. Through the Shabad, they burn away their ego and duality. Attuned to the Name, they sing God's Glorious Praises (sggs 231).
• gurmuiK mrY n kwlu n Kwey gurmuiK sic smwvixAw: Gurmukh marai na kaal na khaaye Gurmukh sach samaavaniaa: The Gurmukhs do not die; they are not consumed by death. The Gurmukhs are absorbed in the True Lord (sggs 125).
• gurmuiK jIvY mrY prvwxu: Gurmukh jeevai marai paravaan: The Gurmukhs are celebrated in life and death (sggs 125).
• jnm mrn kw BRmu gieAw goibd ilv lwgI: Janam maran kaa bharam gaya Gobind liv laagee: The illusion of birth and death is gone; I lovingly focus on God (sggs 857).
  
• mrxY kI icMqw nhI jIvx kI nhI Aws: Marnai kee chintaa nahee jeevan kee nahee aas: (When mind is attuned to the meditation on the Divine) I have no worry about dying, and no craving for living (long life) (sggs 20).
• bRhm igAwnI sd jIvY nhI mrqw: Brahm Giaanee sad jeevai nahee martaa: Brahm Giaanee ever lives and never dies (sggs 273).
  
• jnim mrY so kwco kwcw: Janami marai so kaacho kaachaa: Birth and death are the lot of the false and the insincere (sggs 288).
  
• inj Gir vwsY swic smwey]jMmxu mrxw Twik rhwey: Nij ghari vaasai saachi samaae. Jamman marnaa thaaki rahaae: They (Gurmukhs) dwell in the home of their own inner beings, and merge in the True Being. Their cycle of birth and death is ended (sggs 222).
• mrxY kI icMqw nhI jIvx kI nhI Aws: Marnai kee chintaa nahee jeevan kee nahee aas: (When mind is attuned to the meditation on the Divine) I have no worry about dying, and no craving for living (a long life) (sggs 20).
• jnnI jwnq suqu bfw hoqu hY ieqnw ku n jwnY ij idn idn AvD Gtqu hY: Jananee jaanat sut badaa hotu hai itanaa ku na jaanai ji din din avadh ghatat hai: The mother thinks that her son is growing up; (but) she does not understand that, day by day, his life is diminishing (sggs 91).
  

The Gurmukhs become Immortal for they ever remain immersed in the Naam or God-Consciousness. To the contrary, the Manmukhs remain mortals and experience the pain of death for they ever remain in Mayaic or material consciousness (falsehood). The Gurbani says that even though a Manmukh may grown weary chanting the Naam, but the "filth" of his mind (Kaam, Krodh, Lobh etc.) will not go away. Because, even while doing spiritual practices, his focus remains at the worldly level!

• mnmuK hir hir kir Qky mYlu n skI Doie: Manmukh har har kar thakke mail na sakee dhoi: The Manmukhs have grown weary of chanting the Name of the Lord, but their filth cannot be removed (sggs 39).

• pVxw guVxw sMswr kI kwr hY AMdir iqRsnw ivkwru]haumY ivic siB piV Qky dUjY Bwie KuAwru]so piVAw so pMifqu bInw gur sbid kry vIcwru]AMdru KojY qqu lhY pwey moK duAwru]gux inDwnu hir pwieAw shij ry vIcwru]DMnu vwpwrI nwnkw ijsu gurmuiK nwmu ADwru: Reading and studying are just worldly pursuits, if there is greed and corruption within. Reading in egotism, all have grown weary; through the love of duality, they are ruined. He alone is educated, and he alone is a wise Pandit, who reflects and contemplates the Gur-Shabad. He searches within himself, and finds the true essence; he finds the Door of Salvation. He finds God, the treasure of excellence, and peacefully contemplates Him. Blessed is the trader, O Nanak, who, as a Gurmukh (Spiritual Being), takes the Name as his only Support (sggs 650).

• mnmuK mugD gwvwru iprw jIau sbdu min n vswey: Manmukh mugadh gaavaar piraa jeeou sabad mani ni vasaaye: The Manmukhs are foolish and crazy, O my dear; they do not enshrine the Shabad within their minds (sggs 247).
• mnmuKu pRwxI mugDu hY nwmhIx Brmwie: Manmukh praanee mugadh hai naamheen bharamaai: TheManmukh is foolish; he wanders around without the Naam, the Name of the Lord (sggs 313).
• gurmuiK nwim rqy suKu pwieAw shjy swic smweI hy: Gurmukh naam ratay sukh paa-i-aa sehjay saach samaa-ee hay: The Gurmukh is imbued with the Naam, the Name of the Lord; he find peace, and is intuitively immersed in the True Lord (sggs 1047).
• gurmuiK jmkwlu nyiV n AwvY ]haumY dUjw sbid jlwvY]nwmy rwqy hir gux gwvY: Gurmukh jamkaa nerhi na aavai. Haumai doojaa shabadi jalaae: The Messenger of Death does not even approach the Gurmukhs. Through the Shabad, they burn away their ego and duality. Attuned to the Name, they sing God's Glorious Praises (sggs 231).

— www.gurbani.org