praying / preying are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
praying: (verb) address a deity, a prophet, a saint or an object of worship; say a prayer.
preying: (verb) profit from in an exploitatory manner.
praying: p·r·EY·ih·ng
preying: p·r·EY·ih·ng
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)