NOTES for Luk 3:10
Those who came to John did not ask him by accident what they should do next. John spoke of the Messiah's imminent coming. In Judea at that time many, if not all, were waiting for the Messiah. And many were sure that they were ready to meet Him. There were even more who were not sure of their readiness, but were sure that they knew how to prepare. And the majority were sure that the Messiah's coming would be a feast for them, a feast of meeting God's Servant and a feast of the triumph of the Kingdom whose inhabitants they hoped to become.
And then a prophet appears who says that everything is not so simple. That the meeting may turn out not to be so joyful at all. That, in essence, there are practically no people ready for this meeting. And that very many, if not all, of those waiting to meet the Messiah will have to prepare. In such a situation the question of what to do and how to prepare was entirely relevant. John spoke of conversion and purification. He spoke of them even to those who, in general, had no special grounds to consider themselves unclean. He spoke to those who already believed in the God of Israel. What else is needed?
Conversion presupposed some changes in life. Which ones? This is what those who came to John and believed him asked him about. The prophet spoke of fiery purification, and those who listened to him understood what he meant. Theophany can become for a person a fire that burns him if the person proves unready for the meeting. It was necessary to prepare. And John would tell the people who came to him how to prepare. He proposes nothing especially complicated. No long prayers, no special complex purifying rituals.
The main thing is love for one's neighbor and openness to him. And the matter is not only that without such openness one's neighbors will inevitably suffer. The matter is also that without learning openness in communication with people, it is practically impossible to learn it in communication with God. The skill of openness is much easier to acquire by communicating with a person like oneself than by communicating with God, who is not at all like oneself. And John recommends this as the best preparation for the meeting with the coming Messiah. And as an anticipation of the experience of life in the Kingdom, where openness is one of the main principles.