ah, so you are using this to bash anyone who does not agree with you to help you quit.
very Christian attitude.
The purpose of this thread is for many reasons, but most importantly to establish whether smoking drugs is a personal sin you can commit against your own body, rendering your body a slave to sin.
The nature of your body does indeed belong to yourself, everybody has their own nature. Your nature wants to control your own nature. And your nature will know when something else is trying to control your nature. It's a defense mechanism that the human body has. (the nature of your own body is not designed to let something else control it).
This why your body quickly adapts when a drug of some kind is trying to control the body. Your nature will try to overcome that which is trying to control your body.
Take drinking wine. Like you have a little drink of wine once in a whole year and all of a sudden you become overwhelmed with a merry feeling that feels wonderful. The next day, when you have that little drink of wine, you don't quite get that overwhelming feeling of feeling merry, that's because the nature of your body as quickly adapted to try to control an alien invasion of something else trying to control your nature. The body is trying to reject the wine.
In turn, you think you should have another drink to feel that wonderful feeling of being merry, etc.
After your second drink you feel merry, but the next day you have to drink more than two drinks of wine, and you don't quite get that merry feeling, this is because the nature of your body as already adapted to take control of your own nature, it's like a natural defense mechanism the same as if you get stung by an insect injecting an alien chemical to anyone point in your body, your body will automatically try to expel that alien chemical from the body.
This is the same for cigarettes, you find your self having more and more to feel that relaxed feeling that nicotine can bring, only with nicotine it wins and the nature of your own body can no longer take control its own nature.
The reality, you have now entered an alien funny farm that becomes the norm. As you smoke 20 cigarettes a day you enter your body into a funny farm. But the body soon knows no different and the funny farm becomes a normal reality to your mind, but to the body it still longs for its own nature to return to normal, this is why you will always get a feeling that smoking is just not right.