Ashtavakra Gita 15.19 -

It is first and last the mind that matters in spiritual pursuit. Mind does the entire havoc of agitation and doubt. When agitation subsides, spiritual goal will be attained. This is the crux of seeking, sādhanā and enlightenment.

As one grows after birth, his sensory interactions begin to swell. Mental imprints also increase, arousing endless motivations and instigations. The vicious circle gets stronger every time.

Do not think the world with your senses is the cause of this plight. Anything may be there. Only when your eyes see it and the mind thinks about it, the network of imagination and doubt begins. Mind alone is the cause of all activity, interaction, and whatever follows. Shift the attention from objects and senses to the mind, their motivator, and make your seeking safe and smooth.

Imagination and doubt are the sole outcome mind fetches. Mind first imagines, fosters saṅkalpa, leading to vikalpa, doubt. Mind doubts existence of the Subject, Self, its blissful nature. It doubts whether Self-realization can fulfil one, or the Self too is imaginary! If the world including one’s body is illusory, then will not its witness, the ‘I’ also be? All this deliberation should cease and mind become still and pure. The ‘I’ should be the fundamental presence and all the rest its extension. The ‘I’, the Self is bliss incarnate. Experiencer is the sole fact, all the rest fictitious!