Imagine someone goes around saying that bleach is not poison. Feed it to your kids. Pour it on your salad.
Or "Smoking is GREAT for you". "Give your two year old cigarettes". "Make sure your pregnant wife smokes. Cigarettes are good but dope is better!!!"
Would we be tolerant of such people? Of course not because they are dangerous. We would call them out on everything.
People walk around and try to change the Torah. That is no less dangerous. I recently saw a famous feminist giving a lecture at no less an institution than Harvard. What does she actually know that makes her an authority? NOTHING. Any eighth grader in a good yeshiva day school knows more than she does. All she knows is one thing - that we have to change the Torah according to her standards.
Because she says so.
It is arrogant, it is stupid and it is evil.
There are many such people and some even claim to be Orthodox. Watch out for them because they are the most dangerous.
Another example - here. The subject of this review writes [on a blog I won't link because it is replete with heresy - but trust me] "My solution is to regard belief in revelation as an “as if” statement, a useful fiction (or, in Maimonadian terminology, a “necessary truth”) whose purpose is to represent and engender certain attitudes rather than to describe an objective occurrence.
Meaning, that she doesn't believe that Maamad Har Sinai ever actually happened. עפ"ל. She wears a tichel and eats kosher but when she touches wine one may not drink it because she has the status [in certain matters] of a non-Jew. [I heard that no less an open and tolerant individual as Rav Aharon Lichtenstein publicly called her out on her heretical views to which she responded with ... tears. Happily - she has two sons who are genuine talmidei chachomim.]
There is nothing more important than preserving the purity of our belief system as we have written so many times on these pages.