A Simple Explanation
I believe, the only unforgivable sin is the rejection of Jesus Christ's offer of salvation, His free gift of eternal life, and thus, His forgiveness from sin. If you don't accept His gift, you cannot be forgiven. If you deny the Holy Spirit's entrance into your life, to work His sanctification in you, you cannot be cleansed from unrighteousness. Perhaps this is too simple an explanation, but it is the one that makes the most sense to me in light of the Scriptures.Therefore, "blasphemy against the Holy Ghost" can be understood as a continued and persistently stubborn rejection of the gospel of salvation. This would be an "unpardonable sin" because as long as a person remains in unbelief, he voluntarily excludes himself from forgiveness of sin.

