That is not part of the Gospel. That is a Protestant invention.
And you don't really believe what you wrote because you know that sacraments are necessary for salvation; ccc 1129, all rc dogmas are necessary also right? Can I deny Mary as theotokos (which I do) and be saved? What you wrote and what your church officially teaches are two different things.
One is not permitted to deny what they know to be true. Note that "know" is the key word.