In plain words
That is the inquiry into the principle of the antaḥkaraṇa. It is this that we have been calling negative and positive. The negative is unnecessary for man. You listen to everything that is unnecessary. Once that negative has entered you, sorrows of many kinds keep chasing you. Today all that man longs for is positive, but what he has filled his heart with, full to the brim, is negatives. If you fill the heart full of negatives and want positives, how will they come? A small example of this: the children are singing. Every day they sing to many new tunes. As you watch the tunes, each song seems to have a new spirit. They do these songs and bhajans with stirring rāgas and an eager mind. The tunes are attractive. The words are full of joy. If you look at the matter, it looks very delightful. But what matters is how the heart is. If you keep wicked feelings, animal feelings, beastly feelings inside the heart, will a bhajan become attractive however many kinds of it you do on the surface? The rāgas outside, the tālas outside: all these are only joined with the negative. The feeling within, when it is pure, full, joyful and selfless, is the true positive. So you must try to develop the positive; nothing comes of the negative. Today every man fixes his aim on the negative alone, forgets the positive, and so carries on his daily life. Every act that belongs to the mind is negative; every work that belongs to the heart is positive. You must develop the work of the heart day by day; to develop what belongs to the body is no greatness.
That is why, "Among living beings a human birth is hard to gain": the human birth is a supreme gift received by the will of God. How well we must use such a gift received from God! How carefully we must look after it! How holy we must make our experience of it!