First of all, all deeds are actions, and any action is karma, which may be good or bad, and as such kamas are like seeds sown for which we have to come when they are reap, some may have planted mangoes, so they come to collect mangoes(good karmas = healthy, happy life), others may have planted "mirchi" , so they have to come and collect or eat their own sown seeds of pain and misery, so karmas or deeds are definetely not truthful living...
To view truthful living in the perspective of Gurmat, we have to understand and keep in mind what that Truth is.
The Truth mentioned in Gurbani is the Supreme creator Waheguru Akal Purukh Himself, to which Gurbani is referred as aad Sach, jugaad Sach, hae bhee Sach, Nanak hosee bhee Sach.
So Sach is Nam, which is not a particular word in a particular language, or an exclusivity of any dharam , mazab, or country in time and space.
Rather Nam or Shabad is a creative consciouss power or energy, all pervasive
So truthful living naturally, has to do something with what we engage in by trying to manifest that Truth/Sach within us.
And that definetely truthful living is His simran or Nam bhakti, so naturally we come to a logic concluson, that the devotion or meditation of Nam simran is in essence the truthful living, as it leads us to that ultimate Truth of Nam or Shabad.
In this respect the Bani tells us:
Awar kaaj tere kitay na kaam mil Sadh sangat bhaj kewal Naam.
No other deeds are of any avail, so keep the company of the Holy, and do only the jaap of Naam.
The Bani does not say to rely on good deeds/karmas, in order to realize Him, for as seen above good karmas are chains which keep us also prisoners in the mayavee creation, for we have to come and collect the fruits of those good deeds or karmas sown by us.
The Bani says:
Aapay bheejeh aapay khaae
You eat your own sown karmas.
At other place regarding deeds, good or bad, the Bani tells us:
ਕਰਮੀ ਆਵੈ ਕਪੜਾ ਨਦਰੀ ਮੋਖੁ ਦੁਆਰੁ ॥
Karamee Aavai Kaparraa Nadharee Mokh Dhuaar ||
By the karma of past actions, the robe of this physical body is obtained. By His Grace, the Gate of Liberation is found.
So you see, with deeds whether good or bad, we obtain different bodies in the wheel of 84 according to our merits, but definetely not the Truth of Nam, which is obtained by His grace.
And to add a bit, no one can do His simran by himself or herself, for as the Bani says: Se simrae jis Aap simrae.
Which means, only that being meditates on His Nam, to whom He wants, so you see Pen Jee, it is not in anybody´s hands to do His simran.
That is why, most people have aversion to Nam japnaa, they prefer to do and are ready to do any other things or activities above His Nam simran as seen in the Bani, in almost each ang of it.
Many have the concept that Nam simran is doing a mantra simran or meditation, which is not correct at all.
His Simran is the jugtee which will reveal or manifest the Satnam, Nam or Shabad as the ultimate Truth within us
His simran is the actionless action, thus truly the truthful living, for by engaging in it, we are on the path which will only lead us to that Truth / Sach since the very beginning or in the eternity.
Truthful living can also be seen as His Simran, for as the Bani says:
Jin Har japeeya se Har hoeeya.
This means, whosoever does His simran, becomes one with Him.
The Bani does not say do good deeds in order to manifest that Truth within yourself, rather emphasizes again and again on His simran, if only our purpose is of merging ourselves in Him.
Good deeds or moral living are necessary only to the extent of keeping our vessels (mind) clean, for when the ocassion arises the Amrit of Nam can be poured into our very inner being.
Good deeds is only keeping the vessel clean, which by all means is empty by itself.
Good deeds is not Nam, is not Amrit.
Amrit is poured into us by His grace, but for that our vessels have to be clean.
So the next question could very well be: how can that Amrit of Nam be obtained?
Guru Jee tells us the correct answer in a simple manner:
ਅੰਮ੍ਰਿਤ ਵੇਲਾ ਸਚੁ ਨਾਉ ਵਡਿਆਈ ਵੀਚਾਰੁ ॥
Anmrith Vaelaa Sach Naao Vaddiaaee Veechaar ||
In the Amrit Vaylaa, the ambrosial hours before dawn, chant the True Name, and contemplate His Glorious Greatness.
Bhagat Jan, Gurmukhs, Guru Sahiban.... all of these come at our level from that realm of Ultimate Truth, where nothing else exists but He himself alone.
And they come for the only purpose of awakening us to that reality of Truth/Sach/Nam, by singing His praises; to which we are unaware due to our deep rooted agyanta and manmat.
In relation to whatsoever has been mentioned in this post, I would like to end with some beautiful verses from the Bani of Panchvee Patshahee:
ਅਬ ਕਲੂ ਆਇਓ ਰੇ
Ab Kaloo Aaeiou Rae
Now, the Dark Age of Kali Yuga has come.
ਇਕੁ ਨਾਮੁ ਬੋਵਹੁ ਬੋਵਹੁ
Eik Naam Bovahu Bovahu ||
Plant the Naam, the Name of the One Lord.
ਅਨ ਰੂਤਿ ਨਾਹੀ ਨਾਹੀ ॥
An Rooth Naahee Naahee ||
It is not the season to plant other seeds (good deeds/karmas, poojas, pilgrimages, fasting, torturing oneself, idol worship, keeping quiet, etc .
ਮਤੁ ਭਰਮਿ ਭੂਲਹੁ ਭੂਲਹੁ ॥
Math Bharam Bhoolahu Bhoolahu ||
Do not wander lost in doubt and delusion.
ਮਨ ਰੁਤਿ ਨਾਮ ਰੇ ॥
Man Ruth Naam Rae ||
O mortal, this is the season of the Naam.
ਗੁਰਮੁਖਿ ਨਾਮੁ ਜਪਹੁ ਦਿਨੁ ਰਾਤੀ ਅੰਤ ਕਾਲਿ ਨਹ ਲਾਗੈ ਪੀਰ ॥੧॥ ਰਹਾਉ ॥
Guramukh Naam Japahu Dhin Raathee Anth Kaal Neh Laagai Peer ||1|| Rehaao ||
As Gurmukh, chant the Naam, the Name of the Lord, day and night. At the very last moment, you shall not have to suffer in pain.
Then as a consequence of this truthful practice, following is the result which takes place:
ਜਨ ਨਾਨਕ ਗੁਰਮੁਖਿ ਜੋ ਨਰੁ ਖੇਲੈ ਸੋ ਜਿਣਿ ਬਾਜੀ ਘਰਿ ਆਇਆ ॥੪॥੧॥੧੯॥
Jan Naanak Guramukh Jo Nar Khaelai So Jin Baajee Ghar Aaeiaa ||4||1||19||
O servant Nanak, that person who plays this game as Gurmukh, wins the game of life, and returns to his true home (Sach Khand).
ਗੁਰਮਤੀ ਨਾਮੁ ਧਿਆਈਐ ਸੁਖਿ ਰਜਾ ਜਾ ਤੁਧੁ ਭਾਇਆ ॥
Guramathee Naam Dhhiaaeeai Sukh Rajaa Jaa Thudhh Bhaaeiaa ||
Those who follow the Guru's Teachings meditate on the Naam, the Name of the Lord. Filled with a joyful peace, they surrender to Your Will.
So you see Pen Jee, Guru Jee in each Ang, stresses upon Nam, and its japnaa or simran, to cleanse us from all our karmas/deeds whether good or bad, and at the same time to manifest or reveal that Aad Truth/Sach of Nam, within us, not otherwsie.
Sat Sree Akal.