What Does Purity Mean?

That you are pure and trustworthy with forgiveness of sin.

The purity is a noun and describes a kind of state when somebody or something is pure. The following sentence can make you understand the word well as it describes its use in context: The purity of the water of this tank is tested quite regularly so you don't need to worry about the health. The sentence says that the water has nothing mixed in it and you don't need to fear about your health when you are drinking this water.
       
The word has its derivation in the word pure which conveys something which is virgin and nothing is mixed in it. The word is one of the most widely used words in the English language and has its figurative uses also; you can use it for somebody who is morally right.