Careful when you look at the first verse you've posted. It's caused a lot of trouble!
Just for anyone reading this, although the verse about blasphemy against the Holy Spirit suggests that there is an "ultimate" unforgiveable sin. That if you do this one thing, God will not forgive you.
THIS IS NOT THE CASE!!!!
Once again, the context of the scripture is all important. Our God is god of mercy, and will forgive us all our sins if we truly repent of them. This is written throughout the New Testament.
This still does not make this verse contradictory. Jesus said these words directly concerning the Pharisees and how they claimed he was casting out devils in the name of Satan. What Jesus was getting at was that the Pharisees were so far gone, so messed up and evil that they could confuse the Holiest thing on earth, the Holy Spirit ,with the powers of Satan. It's not that God wouldn't forgive them, it's that they had gone too far, and would never be able to bring themselves to truly ask Jesus for forgiveness.
It does not mean that if you once, in a fit of adolescent spite, said that the "Holy Spirit" doesn't exist, you're going to hell. Not at all. Even slightly.
There, said my piece.
God Bless
Nick