Is the Bible True?, page-500

IMO Blasphemy is a practice that should not be part of a civil code for its punishment.

But having said that, the practice shows it to be an inflammatory, unnecessary, and harmful practice that incites violent reactions from people.

It is best to avoid it.

It is the kind of behavior that creates problems. It serves no purpose other than to enrage the people it is aimed at.

If one is trying to "educate" or persuade someone that their faith is in error, blasphemy is a failure because humans become unreasonable
when they are insulted.

But if people want to be rude, hateful, inconsiderate, spiteful, and inflammatory, they cannot be stopped. These qualities are discouraged by
most religious principles, which for the most part encourage peaceable behavior, respect for others, and kind words and deeds.

The punishment here and now should be no more than excommunication or disqualification from the sect or group that is the target.

God can take care of any further sanctions against the offenders, if God exists.