Believe me, what we have read somewhere will give us the influence to be better or get to be bad. But if we read something gives a negative impact not too long and have a positive influence stronger, the negative impact will be minor.
See the web page that you read often, news you have preferred and what is always take your attention. Notice how your thinking at this time. Believe or not it count influence.
Dirty water by the ink in a glass can not be cleaned by removing ink from water inside. There is only one way to clean it, that is pouring water as much as possible into the glass.
Be careful of reading books. We are what we read, we think what we read, we act what we think, we get what we do and we are what we do.