I'm still working my way through the Life of Messiah series.
Having heard many many explanations of what the unpardonable sin is, I have to say that this one really makes the most sense.
Here's how Arnold Fruchtenbaum defines it:
The national rejection by Israel of the Messiah-ship of Yeshua while He was present here on Earth on the basis of being demon possessed.He goes on to explain this as it relates to the context of the passage and how this sin is not unforgivable in a personal salvation way, but in a national punishment way.
He then sites examples of such a thing is Israel's past including the refusal of Israel to enter into the promised land and the Babylonian captivity.
It makes a great deal of sense when one notices how much Jesus uses the phrase "this generation" after this happens.
He explains that it is at this point that Jesus begins speaking in parables.
|The parable of the leaven|
The two reasons He does so is to keep the unbelieving portion of Israel blinded and to introduce the mystery kingdom (the church) to his disciples.
This particular session helped to clear up many things for me.
Even if you aren't interested in the entire series I highly highly recommend making time for this one.
You can listen or download it here.