In most of his epistles Paul began by setting forth foundational truth and then concluded by applying that truth to the lives of his readers. This pattern is very obvious in Ephesians where the first three chapters deal with doctrine (teaching) and the last three with practice (application). Of course, there is some doctrine in the last three chapters and some application in the first three, but generally this is how Paul organized his material. Compare the Book of Romans in which chapters1-11contain mainly doctrine and chapters12-16 mostly practice. [source][source][source]
The salutation contains Paul"s introduction of himself to the original recipients of this letter and his greeting to them. [source][source][source]