In The Name of Allaah, The Most Merciful, The Bestower of Mercy

In Sharh Hilyati Taalibil Ilm pages 253-254, Shaikh Uthaymeen [rahimahullaah] spoke about the six distinguishing signs of beneficial knowledge, then he stated that the third of them is that a person increases in humility whenever his knowledge increases, so he does not become arrogant towards the people. Then the Shaikh [rahimahullaah] said:

If there is a clash between humbling oneself to the truth and humbling oneself to the people, then one should give precedence to humbling himself to the truth.  For example, if there is a person who curses [or abuses, reviles etc] the truth and rejoices due to his enmity against the one who acts upon the truth, then in this case one should not be humble in the presence of this person; rather one should humble himself to the truth and debates this man [i.e. the one who abuses the truth]; even if he belittles or speaks against you, do not give concern to what he says [or to him], because the truth must be aided. [paraphrased]