- But when the Pharisees heard this, they said, This man casts out demons only by Beelzebul the ruler of the demons. - Matthew 12:24
Beelzebul or Beelzebub is a deliberate distortion of the name Baal-Zebul. Baal-Zebul was a Philistines god, considered the lord of the flies (cf. 2 Kings 1:2). Historians believe that this deity communicated through the buzzing of a fly and protected its worshippers from plagues associated with flies. The Israelites deliberately distorted the name to Beelzebub, which means the lord of the dung. They also applied the name Beelzebul to Satan. It was a common practice amongst the nations of their era to associate the gods of enemy nations with the devil.
In reality, Jesus healed the man and performed all His miracles through the power of the Holy Spirit, not Satan.
- Jesus, full of the Holy Spirit, returned from the Jordan and was led around by the Spirit in the wilderness […] And Jesus returned to Galilee in the power of the Spirit, and news about Him spread through all the surrounding district. - Luke 4:1, 14
To accuse Jesus of doing miracles through the power of Satan was to blaspheme the Holy Spirit. Blasphemy (blasphēmía) is speaking evil reports to wound someone’s reputation. Thus, when the religious leaders accused Jesus of healing in the power of Satan, they injured the reputation of the Holy Spirit by accusing Him of being Satan. It is this blasphemy of the Holy Spirit which is unpardonable or unforgivable.
- Therefore I say to you, any sin and blasphemy shall be forgiven people, but blasphemy against the Spirit shall not be forgiven. Whoever speaks a word against the Son of Man, it shall be forgiven him; but whoever speaks against the Holy Spirit, it shall not be forgiven him, either in this age or in the age to come. - Matthew 12:31-32