What is the sin that God does not forgive?

What is the sin that God does not forgive? The Lord will not forgive us for grieving the Holy Spirit. In the early church, the disciples sold everything they had and collected it and put it at the apostles' feet. Ananias and Sapphira put aside what they had. The rest he put at Peter's feet. In fact, they put Peter's foot in the door saying that it was all theirs. It was a lie to the saint and left the souls of both in real time. If it had been said that it had been set aside a little, the liar would not have come to the Holy Spirit. He would not have died. Dear children of God, do not be tempted to lie to the Holy Spirit who knows our mental state well.