Answer:
Not really.
Explanation:
"Preaching" is a religious term, and it is the delivery of a religious address/moral advice to an assembled group of people, typically in church.
In other words, it is giving a religious speech about the word of God, and trying to persuade other people to believe in a particular belief/follow a particular way of life.
"Talking" is merely a casual term that is informal, and does not necessarily fit in this situation.
I hope this helped! Let me know if you didn't understand some parts, I'll try to define it in an easier way.
~Jinachi~