In plain words
If we want to recognise holy divinity, we can see it only through the holy mirror called ‘Prema’. In the worldly story, people think of today as the slaying of Narakāsura. If we look into this worldly story a little, we come to know that Naraka was a demon, that he went on tormenting many women, that he brought many people under his power and imprisoned them, and that, ever full of attachment and hatred, he took the physical joy of the body for lasting joy and ruined his life.
One who has bad qualities is destroyed by those very bad qualities
Narakāsura's anger was very great. We keep bringing in many kinds of ways to wipe out this anger. But God found an easy way for it. The more anger rises in a man, the more the strength of the senses in him is drained away. Once a man gets angry, the strength of three months of eating wastes away. In this way all the nerves grow weak through anger. What we can understand well in daily life is this: when a man gets angry, his whole body shakes. The whole body heats up. The lips and hands tremble. Little by little the blood grows hot. It takes a long time for this heated blood to cool. This blood heats up and in the end drains the senses of their strength. Narakāsura's anger knew no bounds. Wishing to cool his anger, calm his senses and drain away his strength and might, Kṛṣṇa again and again went to battle against Narakāsura and, when he came on in anger, turned and came back: this is how it went. People who looked with worldly eyes went on thinking, ‘Alas! Kṛṣṇa is running away at the sight of Narakāsura.’ In this way, because Kṛṣṇa went to battle against Narakāsura again and again, made him angry and Himself came back, little by little the strength in Narakāsura drained away completely.