So here we have people who heard God’s word and were saved.
Remember, it was still not popular to be identified as a Christian, but the show that this was an actual salvation, they were water baptized.
If this were just an emotional response, most would have probably not set themselves up to ridicule for something they really didn’t believe.
Remember this as we get further into the account.
But in amongst the believers, you will always have those who follow for their own benefit. “What’s in it for me”?