Most Christians I think go through a period where they think they committed the sin of Blaspheme against the Holy Spirit, but have not. I know I did when I was a young person. I suffered with blaspheme thoughts directed to God and became quiet sick over it. Now I know I was just being attacked by the devil. It was him making out the blaspheme thoughts were my thoughts. When they were really him putting those thoughts into my head. Without me wanting them there. Many Christians are having this problem. So don’t be disturbed.
What is blaspheme against the Holy Spirit according to Clare from the Small Still Voice? Jesus explains it is someone who knows God exits, but still preaches against God to everyone. They deliberately turn people away from God, even after a personal experience of Him. These people can still be saved if they turn back to God, but they will have a stain on their garments for eternity. So it is people who once knew Him and became His enemy despite knowing His love and mercy.