Many in our day will argue stating sound doctrine is not essential for Christians. These same people oftentimes are worldly and filled with unrepentant sin, having a form of godliness but lacking the power. Here's an example; my daughter was flabbergasted by a classmate who is homosexual and yet has a tattoo of a cross with 'Jesus is my Savior' inside the cross. She wondered how this could be, keep in mind, my daughter is not saved. This is an example of adhering to wrong teaching.
Here is an excellent article from A.W. Pink on the importance of right teaching....
"Afresh, precious, precious Jesus, I resign this body to You, for doing or suffering, for living or dying. Will You accept it? Will You use me for Your glory more than heretofore, that You may have some little return for all the benefits You have done to me? Oh, do grant this request; my heart longs for it, my spirit pleads for it; and "if You will, You can." You know the hot temptation of which I am the subject. Bring Your glory out of it, and keep me from the evil, and it shall be well." - Ruth Bryan