Anyone who willfully refuses to listen to *whatever* God teaches through the Church loses their salvation. Period. Heresy is a grave, grave sin.
And God tells us that just where in Scripture?
Or did He forget to include that as well so the Catholic church had to (oh so conveniently) fill in the blanks for God with their conjured up *sacred tradition*?
I would expect the Catholic church, just like any religion or religious system to consider opposition to it a *grave sin*. It's a great tool for controlling the masses.
But heresy against CATHOLICISM is no sin at all. God doesn't mention it at all in Scripture.
And the Catholic church cannot just make sins up to slap on people and condemn them over.
Anyone who follows the word of mere men over the Word of God is in a bad way and will live to regret it.