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 unpardonable sin is identified here as blasphemy against the Holy Spirit. Jesus our Lord had performed a miracle and yet the Pharisees attributed the work of the Holy Spirit to be the work of the devil.
Our Lord rebuked 5 out 7 churches in Rev 2 and 3 for their sin and ended with this exhortation, “Whoever has ears, let them hear what the Spirit says to the churches.” And culminated in Rev 3:19 which is very clear that Jesus or His Spirit will reprove and convict the Christians of sin and call for us to be zealous and repent.
(Those whom I love I rebuke and discipline. So be earnest and repent. Rev 3:19.)
It is bad enough to deny this work of the Spirit of Jesus to convict a Christian of sin but to attribute it to the work of the devil will be utter blasphemy similar to the above incident told in the Scripture to specifically warn us.
The false cheap grace teachers have preached that the definite and marvelous work of the Spirit in convicting us of sin is actually the work of the devil in robbing us of joy by making us sin conscious.
They are even audacious enough to say that all the theologians and pastors in the past had got it so wrong about the conviction of sin by the Spirit of Jesus and the need to confess our sins.
They have confused guilt with contrition. Or the confusion of their followers may be deliberate. Guilt is bondage but contrition is true worship. Ps 51:17; Is 66:2.