What is Blasphemy of the Holy Spirit?
In the context of what Jesus spoke about it, it was the religious teachers seeing Jesus cast demons out of people and saying that He was doing it by the power of the devil (Beezelbub). What this means that if anyone attributes the supernatural work of the Holy Spirit to the devil, they are blaspheming the Holy Spirit.
We are seeing "respected" Bible teachers accusing Pentecostals and Charismatics of being motivated by the devil when they speak in tongues, and that the signs and wonders in the P/C movement are connected to the lying signs and wonders done by the Antichrist and the Beast. These teachers have also accused Holy Spirit prophets of being the type of false prophet described in the Old Testament merely because they differ in doctrine. This implies that these prophets are also inspired by Satan instead of the Holy Spirit.
I firmly believe that these accusations amount to blasphemy of the Holy Spirit, and it places these "respected" Bible teachers in danger of being rejected by Christ at His judgment seat. Anyone who accuses a believer who speaks in tongues in faith believing that he or she is truly communicating with God, of being inspired by Satan is blaspheming the Holy Spirit and is motivated by a lying, accusing spirit, and in so doing, is bringing destruction upon himself.
The instruction from God, "Touch not My anointed", is very relevant in these days. We have anointed healing and prophetic ministries coming under criticism and accusations of being "false prophets", and yet these ministries are winning thousands of lost souls for Christ, for in excess of any results the churches of these accusers are achieving. All some of these accusers are doing is setting up websites for the express purpose of running down anointed ministries. I believe that when the people who have those websites come up before Jesus, He will say, "Depart from Me ye wicked. I never knew you." Anyone who runs down a ministry that is undeniably anointed by the Holy Spirit, and accuses it by implication that it has a demonic foundation (and what other foundation could they be saying it has if they don't believe it is the Holy Spirit?), is blaspheming the Holy Spirit.
Blasphemy of the Holy Spirit is a deliberate act, as I have just described. The devil can put lying thoughts into anyone's mind to dislodge them from their faith in Christ, but a good believer can recognise it as such and tell the devil to take his thoughts and "get on his bike!" We can't stop birds landing on our heads, but we can stop them nesting there.