The Bible is full of promises. Some of them have a negative component while others are partially positive and partially negative, like the following promise:
". . . no good thing does he [the Lord God] withhold from those whose walk is blameless." Psalms 84:11 (NIV)
Currently there is much talk and many books written about focusing only on the positive. One of the main tenets of this positive thinking system is that if you focus on not committing some unwanted behavior, by focusing on what you don't want, you eventually get just that, what you don't want.
The above text promises blessings and encourages moral living, but it does so by dealing in negatives. Note especially the double negative of "no good thing" and "withhold," as well as appeal to a state that is free from blame, which in itself is a negative concept.
The purely positive version of this excellent promise might be something like "the Lord will bless you beyond your wildest imagination if you live a moral life." The important thing to keep in mind is that without the forgiving love (grace) of God, no one can live a moral life.
The full prayer might be "Lord, enable me to live a moral life by your transforming grace and continue to bless me greatly in my life."