Smile, according to your question
If a man blaspheme against the holyspirit and then realized what he did was wrong
That means at first he was ignorant and now realized his mistake, he will definitely be forgiven
God want us all to be saved and he's a merciful God like you say
But to those that already heard the gospel, heard about God, already knew the doctrines of God and also the law and still speak against the holyspirit, to them theirs no forgiveness.
Thanks