Jesus and Beelzebub
22 Then they brought him a demon-possessed man who was blind and mute, and Jesus healed him, so that he could both talk and see. 23 All the people were astonished and said, "Could this be the Son of David?" 24 But when the Pharisees heard this, they said, "It is only by Beelzebub, the prince of demons, that this fellow drives out demons."
25 Jesus knew their thoughts and said to them, "Every kingdom divided against itself will be ruined, and every city or household divided against itself will not stand. 26 If Satan drives out Satan, he is divided against himself. How then can his kingdom stand? 27 And if I drive out demons by Beelzebub, by whom do your people drive them out? So then, they will be your judges. 28 But if I drive out demons by the Spirit of God, then the kingdom of God has come upon you.
29 "Or again, how can anyone enter a strong man's house and carry off his possessions unless he first ties up the strong man? Then he can rob his house.
30 "He who is not with me is against me, and he who does not gather with me scatters. 31 And so I tell you, every sin and blasphemy will be forgiven men, but the blasphemy against the Spirit will not be forgiven. 32 Anyone who speaks a word against the Son of Man will be forgiven, but anyone who speaks against the Holy Spirit will not be forgiven, either in this age or in the age to come.
33 "Make a tree good and its fruit will be good, or make a tree bad and its fruit will be bad, for a tree is recognized by its fruit. 34 You brood of vipers, how can you who are evil say anything good? For out of the overflow of the heart the mouth speaks. 35 The good man brings good things out of the good stored up in him, and the evil man brings evil things out of the evil stored up in him. 36 But I tell you that men will have to give account on the day of judgment for every careless word they have spoken. 37 For by your words you will be acquitted, and by your words you will be condemned."
Blasphemy of the Holy Spirit is a feature of the Pharisaical WT. They say speaking in tongues and other gift of the Holy Spirit are manifest by unclean spirits.
That is the only "unpardonable sin".
All the best,
Stephen