Matthew 12:30-32

He who is not with Me [once and for all on My side] is against Me; and he who does not [unequivocally] gather with Me scatters. [Luke 9:50; 11:23] “Therefore I say to you, every sin and blasphemy [every evil, abusive, injurious speaking, or indignity against sacred things] will be forgiven people, but blasphemy against the [Holy]Spirit will not be forgiven. Whoever speaks a word against the Son of Man will be forgiven; but whoever speaks against the Holy Spirit [by attributing the miracles done by Me to Satan] will not be forgiven, either in this age or in the age to come. [Mark 3:29; Luke 12:10]