Nobody can blaspheme against an energy force, but they certainly can be extremely foolish in their attempts to use it. Whenever a religion claims to have God's power to the extent that no other religions have it, and that all who want a share in that power must come to them to receive it, you know you are dealing with an incredibly foolish group. That is what's going on with the JWs.
Their leaders say they are specially anointed with holy spirit; they are part of the elite 144,000 people who will be the only ones from Christ's time onwards to get to heaven, to be kings and priests with Christ. All others who please God can only expect to live forever on a paradise earth, under their rule. They tell those millions that if they work hard, studying their literature, going round the doors, attending as many meetings and assemblies as possible, and never disobeying them, their leaders, they can get more and more holy spirit. I wonder if that is approaching blasphemy?
Certainly it's worth reminding people that 99.9% of all JWs cheerfully admit that they are not anointed with holy spirit, nor do they think they need to be. They are working hard to earn more of it, you see. They don't want to go to heaven, to see Christ, they are carnal people who love fleshly, material things. Don't let all their spiritual talk fool you. They are just not interested in heaven. That proves they do not have the anointing of God's Holy Spirit! What a horrifying state to be content with! Who will tell them that, unless they are born again of the Holy Spirit, they cannot even see the Kingdom of God?