Beautiful verses from Vivekachudamani of Adi Shankara
Translation of Swami Madhavananda
वदन्तु शास्त्राणि यज्ञन्तु देवान
कुर्वन्तु कर्माणि भजन्तु देवताः
अत्मैक्यबोधेना विनापि मुक्ति
र्न सिध्यते ब्रह्मशातान्तारेपी
vadantu shAstrANi yagyantu devAn
kurvantu karmANi bhajantu devatAhA
Muktirna sidhyate brahmashatAntarEpi
Let people quote the scriptures and sacrifice to the gods,
Let them perform rituals and worship the dieties,
(Yet) there is no Liberation for anyone without the realization of one's identity with the Atma.
No, not even in the lifetime of a hundred Brahmas* put together.
* Lifetime of a Brahma - is an indefinite length of time. One day of Brahma is equivalent to 432 million human years.
sarvadA sthApanam buddheha shuddhe brahmANi sarvadA
tat samAdhAna mityuktam na tu chitasya lAlanam
Not** the mere indulgence of thought in curiosity, but the constant concentration of the intellect on the ever pure Brahman is what is called samAdhAna or self-settledness.
** Not the... - That is, not the mere thinking or intellectual or philosophical satisfaction in thinking of or studying the Truth. The intellect must be sought to be resolved into the higher activity of concentration on the Truth