What does it take to know the truth? The truth is written in gurbani. Once we understand gurbani, we come to know the truth isn't it? I don't see why this truth has to vibrate within every cell of the body, like some have described (on other threads). If I study acetylcholinesterase inhibitors, I come to learn the truth about these drugs. I don't have to meditate upon it.
When I do something kind for someone, from the bottom of my heart, I find that I am not afflicted by any of the 5 thieves in that moment. If such kind gestures are repeated, they become a part of your character. You are not driven by lust, anger, greed, attachment, or ego. You are simply driven by a desire to do seva and ease the suffering of others. If everyone treated each other with kindness and respect, we could bring about Satyug.
These two aspects make up "gyaan" and "dhiaan" (wisdom and attention). Gyaan comes from gurbani and dhiaan is toward the service of creation.
I feel that Guru ji placed truthful action above all else. This is why Guru ji criticized the Nath Yogis. Even though they spent their time in meditation, they did nothing to uplift humanity. Accordingly, gurbani makes reference to Chitr and Gupt, and Dharam Raj. Chitr and Gupt are the deities that keep track of the actions of mortals. Dharam Raj is the judge that decides the mortal's fate (figurative references). Gurbani also mentions that actions done repetitively are engraved on the soul.
The slogan of the Khalsa under Banda Singh Bahadur's leadership was "Degh Tegh Fateh" (victory of the kettle and the sword). This is also why we wear the kirpan. There are so many things in our philosophy that demonstrate we are a faith based around righteous action above all else.