That being said, the Bible is also very clear that the abuse of alcohol, i.e. drunkenness, is a sin, and many warnings are given against it. God commands us to be sober-minded and self-controlled, and drunkenness militates against both of those virtues.
The same prohibition and the same problem holds true with “smoking legal substances.” The particular problem here is that it is almost impossible to use without suffering the same impingement of mental faculties for which God condemns drunkenness.