In plain words
God is present equally in human beings and in worms, insects and the like. If you ask now where God is.... He is in you too. Wanting to learn the answer to this question, many people practise dhyāna and many other kinds of sādhana besides.
Listening, singing, remembering Viṣṇu, serving His feet, salutation, worship, service, friendship and the offering of oneself:
Nārada said that God can be reached by these nine paths. God is in your very heart. Is dhyāna needed to see such a One, who pervades all and dwells within all? Today some teachers give out many methods for doing dhyāna. But whether it is dhyāna or any other sādhana, we do it solely for purity of mind. All these kinds of sādhana in the world come into being for purity of mind and nothing else. Only when there is purity of mind does the vision of God come. Without purity of mind, however many sādhanas you do, God is not attained.
In truth, no sādhana at all is needed to see God. Imagining that God is apart from you, you take up sādhanas such as fasting and dhyāna in order to see Him. Whether you believe it or not, God is right within you. Not only that: He pervades everywhere. But He does not show Himself to those who lack purity of mind. To see God, you must purify the mind. We do so many sādhanas only for purity of heart. Man must pray to God for a pure heart. Just as a vessel grows bright as you scour it, so the more you pray to God, the purer the heart becomes. It is not enough to sit alone in a room with your eyes closed doing dhyāna. You must see God everywhere. God is right within you; He is all around you. But gurus who teach you this truth are very rare.