A new, very interesting sefer called מסורת משה was recently published. It is a collection of answers Rav Moshe Feinstein gave to questions he was asked, written by his grandson. It is easy to read and hard to put down once you have opened it up.
One of the thousands of gems: Some years ago a Jew wrote a sefer of close to a thousand pages trying to prove that it is forbidden to shave one's beard. He asked Rav Moshe to give him a haskama on the sefer but was rebuffed. Rav Moshe emphatically told him that his sefer is against 1] The gemara [which explicitly permits shaving with certain instruments 2] The Rambam and 3] Jewish practice. He explained to the author why his reasoning is faulty and told him that if he wants he can publish the sefer but it is against the Torah to say what he says.
Rav Moshe agreed that it is BETTER to have a beard but certainly not an obligation. What I find instructive is that the author neglected to publish Rav Moshe's rebuttal and admit that the world renowned posek hador strongly disagreed with him.
This to me is another example of people who have negiyos [biases] which prevent them from admitting the truth.
The mussar sefarim talk at length about how we are ALL filled with negiyos which obscufates the truth from our eyes. THAT is a good topic for another post.....:)
As for me I will gladly keep my untrimmed beard but not look down upon those who follow the strict halacha.