Spiritual Enlightenment Question: NOt Thinking?

How is this productive? How is it productive not to think? The still mind is good but what about if someone offers you drugs. Do you just stay still minded and just take it? obviously not, but this is why thinking is crucial. Why then to spiritual teachers tell you not to think? NOt htinking can get you into a lot of trouble. Can someone clarify, maybe i do not understand completely this spiritual thing.