In plain words
The chief aim of sādhana is nothing but setting the mind on the right path. In the world many people practise many sādhanas. All of them give only a passing satisfaction of the mind. Only when one recognises the principle of 'I' does true satisfaction come. Unable to recognise the principle of God, man imagines many forms and names for God and offers worship.
For Him who spreads through the whole cosmos, is it possible to raise a temple? For Him who moves in all living beings, is it possible to give a fitting name? For Him who moves in all the waters, is it possible to give a bath? For Him whose light outshines a crore suns, how can they set out a little oil lamp? When the whole cosmos lies in His belly, is it fitting to serve Him food and sweets?
The Veda teaches, “I am one; let Me become many,” and “What is, is one; the wise speak of it in many ways.” What exists is one alone, and that is 'Aham'. The mind alone imagines forms and names of many kinds for this 'Aham'. This mind plays games of many kinds. Catching hold of the mind is beyond anyone's power. Flies and mosquitoes settle on everything, but they will not go near fire. In the same way, the mind roams everywhere, but on God it does not stay. Above all, this is what man must do: strive to keep the mind fixed on God, pure, steady and selfless. That is true sādhana. In the nine paths of Bhakti, “Śravaṇaṃ kīrtanaṃ viṣṇoḥsmaraṇaṃ pāda sevanaṃ vandanaṃ arcanaṃ dāsyaṃ snehamātmanivedanam”, the chief thing is to offer the mind to God.