In plain words
Emperor Bali was the grandson of Prahlāda; so Bhakti for Viṣṇu came to him through his very line. When Vāmana took the form of Trivikrama and covered earth and sky, he praised Him: “Is it possible to find You?” “You are subtler than the atom, exceedingly subtle. You are greater than the vast, exceedingly great; among thieves You are the master thief!” So he danced and sang, and won Ānanda. World-famous thieves steal only goods and vehicles and the like; the one who steals the citta, holy, pure, more precious than anything, is truly the ‘master thief’, is He not? All of you, from so far away, bearing so many hardships. That you have gathered here with the holy longing to be right in Swami's presence on this festival day is a small proof of the līlā of the Paramātma, who has stolen your citta.
The Prema of God is a great river, and into it the feelings of Prema of each one of you flow like little canals; Prema itself is God; to love is itself the worship of God. The rivers of human Prema mingle, reach the ocean of Grace called the Prema of God, and merge in it.
At this festival in Kerala you eat the “nendra” banana, do you not? But before eating it you have to take off its peel, do you not? Before you eat an orange, too, you must do the same. Is that not so? The Bhāgavatam declares that before accepting the Bhakti of Emperor Bali, God took off the peel called his brute strength, the strength of his wealth, the strength of his authority and his Ahaṅkāra. Casting off all the strengths of “Bali”, God accepted only his pure citta.
This is the purpose with which the people of Kerala keep the Onam festival: people should take Emperor Bali as their ideal and their support, offer the Ānanda of their own Ātma to God, and so make their lives worthwhile. Every year you keep “Onam” and hold only the farewell, but you do not welcome good qualities, good thoughts and good deeds; only when you do that. Your keeping of the festival of “Onam” is fulfilled.
Your good fortune is good fortune indeed; people of other regions have not had the chance so far. They too have their national holy days. Yet that the people of the one state of Kerala alone have the chance to celebrate their ‘Onam’ in Swami's presence, year after year: this, you may truly say, is the good fortune your Bhakti and prapatti have won you.
One more thing: wherever Bhakti for God is seen most, right there feelings and actions against it flare up. In Kerala such feelings are strong. But you, without losing hope. Without losing heart, you must stand up to them and make your śraddhā and Bhakti shine. Only when a diamond is cut does it shine well, in all its splendour. Seeing the conduct of each of you, even atheists will turn into believers, truly. There are no atheists at all; Ātmārāma dwells in the seat of every heart; the nature of Satya in them, the feeling of Prema: all these are the very marks of that Ātmārāma. There is no one without Prema; that Prema itself is God. If you conduct yourselves with Prema, you can lead everyone on the good path.