Matthew 12:31-32 (NIV)
31 And so I tell you, every kind of sin and slander can be forgiven, but blasphemy against the Spirit will not be forgiven. 32 Anyone who speaks a word against the Son of Man will be forgiven, but anyone who speaks against the Holy Spirit will not be forgiven, either in this age or in the age to come.
The one sin that is unforgivable by God is blasphemy against His spirit. This is bearing false witness against God. In other words, giving credit to something else for something God has done... or giving credit to God for something that is clearly not of God.
The Apostle Paul specifically spoke on this as well in his day in
Romans 2:24. He called out those (Jews who were converted to Christianity) who had the written code (the law) and claimed to be children of God... but their actions, before receiving Christ, rejected God and Rejected Christ because they were not walking in God's truth as children of God should. Therefore they could not recognize the written code (the law) in living form (Jesus). They were hypocritical people who tried to hold everyone else to what they could not do and were unrepentant in not doing what they held everyone else to. They wore the T-Shirt as children of God... but they did more to drive people away from God by their actions which were not of God, yet claiming it was God.
24 As it is written: “God’s name is blasphemed among the Gentiles because of you.
And so we have the same scenario today among people who say they are Christian. The actions of some do not resemble Jesus in anyway, yet the claim is this is what it is to be Christian. Many...many people...who see the hypocritical nature of these individuals and self righteous indignation reject this brand of Christianity. Heck... I would not want it either if that is what it is. Thankfully, I know what the word says and can recognize the word in living and breathing form and when something is not the word. But unfortunately, there are many who are not at that place and have based their decision not to follow Christ on what they have seen some Christians do. I support them 100% regarding rejecting what some have tried to get them to believe... but they have made a huge mistake by rejecting Jesus. It's ok to reject the people who are hypocritical... but don't reject following the ways of Jesus. You may not want that brand of hypocritical, self righteous Christianity. I am a pastor and I reject that too... but to know Jesus is to know that what some have been demonstrating is not of Jesus. Reject their ways... but don't reject Jesus. His ways and following it leads to truth and will expose the ways of those who are blaspheming God. This is why it is written that the truth sets you free. There are people who have tried to use the word of God to support and hold up doctrines of devils. The word is truth but how some presented it was half truths that kept people in bondage...both mentally and physically. The word of God says the devil masquerades as an angel of light (2 Corinthians 11:14).. This means he presents the word to unsuspecting people to twist its meaning to keep people in their bondage. He never presents the whole word which sets a person free from bondage. Those who have used the word and twisted it for selfish gain are blasphemers of God... and that penalty is eternal death. This is why you see such a fight to hold on to the things of this world for some. This is all they have. They are trying to be rulers of a dying place. And those who are anchored in a dying place... get what this place is getting.