A Voice from the Past - Augustine

(I was not able to find a quote from Berengar, but I offer this quote from Augustine, which though on another subject, seems relevant to this one.)

But when he saith, "Moses meant not what you say, but what I say," yet denieth not that what each of us say, may both be true, O my God, life of the poor, in Whose bosom is no contradiction, pour down a softening dew on my heart , that I may patiently bear with such as say this to me, not because they have a divine Spirit, and have seen in the heart of Thy servant what they speak, but because they be proud; not knowing Moses' opinion, but loving their own, not because it is truth but because it is theirs.Otherwise they would equally love another true opinion, as I love what they say, when they say true: not because it is theirs, but because it is true; and on that very ground  not theirs because it is. But if they therefore love it, because it is true, then it is both theirs, and mine; as being in common to all lovers of truth.

Augustine of Hippo, 354-430 AD, The Confessions, Book XII, Chapter XXV, 34, (translated by E. B. Pusey,  Barnes and Nobles Books, 1999, p. 306).

How can we avoid loving opinions not because they are true, but because they are ours? What are the warning signs?