Every human being has thought even children do have thoughts so therefore no body is without a thought, and thoughts are feelings and feelings could be either negative or a positive, positive feelings are something normally easy to control than that of negative feelings, now that of negative feelings can be controlled only by the grace of God that he has bestowed on us.
Positive thought are said to be good at times they say, now looking at this, is it because the thought are positive? Is that what made them good? or is it something else?. Remember that even in the act of trying to do something good we end of doing something bad. now then what do we say, we simply can conclude that the thought could be good but the act of carrying out the action of that thought could lead or produce a bad or a negative result, same also for negative thoughts leading to something positive. For instance(negative thought leading to something positive) take someone having the desire to steal a money just to be able to paid the hospital bills of maybe let say his sick mother now are we going to say that the end product of that thought is good itself? well I think you should try answering that yourself, but to me i will say that every product of a negative thought is also a negative itself whether it was done to achieve something good.
Learn to be the master of your own thoughts and action. Each person's must learn how to control his/her thought. As human, we know that we can't actually do or achieve anything in life by our own power this is why each person's having that difficult in controlling their negative thought most especially should learn to pray about it and then try meeting either a friend, someone you trust, or a trained person in that field that would help a lot In overcome that difficulty.