By denying the Holy Spirit. By denying Christ. By denying the holiness of Mary, the Mother of God. By denying the holiness of the saints. . By deny the Catholic Church. By denying the Apostles and St. Peter as the first Bishops and the first Pope.
And many other things
By denying Christ and EVERYTHING connected with him.
Huh. I guess I'm guilty of, well...all of the the above.
Oh, well.
Just as an aside, as I read your list, that would mean that anyone who affiliates themselves with a Protestant denomination rather than a Catholic one has committed an unforgivable sin, and will accordingly roast in Hell. Is that correct, or am I misreading it?