This is what I thank. You can find the answer in Luke 21:12-15
12.But before all these, they shall lay their hands on you, and persecute
you, delivering
you up to the synagogues, and into prisons, being brought before kings and rulers for my name's sake.
Why are they going to deliver you up? For My Name's sake. No other reason.
13. And it shall turn to you for a testimony.
This is going to be a time for you to step up and be a voice for God.
14. Settle
it therefore in your hearts, not to meditate before what ye shall answer:
You are not to thank about what you will say; you are to allow you heart you spirit to do the speaking. What Spirit should be in your heart if they are delivering you up? Lets find out.
15. For I will give you a mouth and wisdom, which all your adversaries shall not be able to gainsay nor resist.
For I: Who is the I? Who is speaking here? Jesus. He is going to give us a mouth to speak with and the wisdom that will come out of that mouth. How does He do that? Through the Holy Spirit. It is going to be the words and the power of The Holy Spirit coming out of your mouth that your adversaries shall not be able to gainsay (King James Dictionary:
GAINSA'YER, n. One who contradicts or denies what is alleged; an opposer.) that are not going to be able to resist.
This is the unforgivable sin. When you stop the work of the Spirit of God.
Matthew 10:16Behold, I send you forth as sheep in the midst of wolves: be ye therefore wise as serpents, and harmless as doves.
17But beware of men: for they will deliver you up to the councils, and they will scourge you in their synagogues;
18And ye shall be brought before governors and kings for my sake, for a testimony against them and the Gentiles.
19But when they deliver you up, take no thought how or what ye shall speak: for it shall be given you in that same hour what ye shall speak.20For it is not ye that speak, but the Spirit of your Father which speaketh in you.
We find the same thing said here as in Luke 21.
Mark 13:
11But when they shall lead
you, and deliver you up, take no thought beforehand what ye shall speak, neither do ye premeditate: but whatsoever shall be given you in that hour, that speak ye: for it is not ye that speak, but the Holy Ghost.
There we have it again. What is the unforgivable sin? To deny the Holy Spirit.