"Jesus answered them, and said, My doctrine is not mine, but his that sent me." John 7:16
We would do well to test the doctrines to which we cling. It is easy to get swept into the doctrine of men and then cling to it with a vice-grip, not even weighing it against God's Word to see if the doctrine is of God. A good test is to consider verse 18 of this passage, "He that speaketh of himself seeketh his own glory: but he that seeketh his glory that sent him, the same is true, and no unrighteousness is in him."
Whose glory are we seeking? When someone contradicts a doctrine (or belief, conviction) that we cling to, what is our reaction? Are we grieved because such does not glorify God -- or merely upset and try to prove that our way is right?