Why would anyone be afraid of the doctrine of Christ. If one is ignorant of the scriptures then they have not the doctrines of Christ nor the indwelling of the Holy Spirit in whom we receive Spiritual knowledge given by the Holy Spirit either directly or working through others to teach us. The doctrine of Christ is that of what God gave him to speak and commanded him to do as Jesus never spoke or did anything that God did not give Him to speak and do.
John 12:47 And if any man hear my words, and believe not, I judge him not: for I came not to judge the world, but to save the world.
John 12:48 He that rejecteth me, and receiveth not my words, hath one that judgeth him: the word that I have spoken, the same shall judge him in the last day.
John 12:49 For I have not spoken of myself; but the Father which sent me, he gave me a commandment, what I should say, and what I should speak.
John 12:50 And I know that his commandment is life everlasting: whatsoever I speak therefore, even as the Father said unto me, so I speak.