We life by Grace, not my Law.

Decide on a behaviour you want to change.  Maybe you want to exercise more, or you want to quit smoking, or you want to quit staying up so late looking at the internet.  Whatever it is, decide you want to change it.

Go and get a reward for when you do what you want.  For example if you want to go to bed earlier, each time you do go to bed earlier you get a reward (maybe one candy, a cookie, or you get to watch a show on DVD).

For one week, give yourself the reward, only if you do the desired behaviour.  This will be living under law.

For one week, give yourself the reward every day, whether you do the desired behaviour or not.  This will be living under grace.

Now it does seem that by living under the law, you will do the desired behaviour more often. That is not necessarily the case.  The case is, that by living under grace, the desired behaviour will become more desirable, and the undesired behaviour won’t be as enjoyable.

Try it for yourself and see.