I asked google AI to write a outline of the book of Ephesians about the Church, a short outline by chapter. Here is the results: (I added the bold)

The Book of Ephesians presents the church as the body of Christ, a unified, multiethnic community created by God through the gospel to display His wisdom. The first three chapters outline the theological position of believers “in Christ,” while chapters four through six detail the practical “walk” of the church in unity, holiness, and spiritual warfare.

Chapter 1: The Church as Christ’s Body. Paul praises God for spiritual blessings, stressing that the church is chosen and adopted to be the body of Christ and the fullness of Him.
Chapter 2: The Church as God’s Household. Describes reconciliation through grace, uniting Jews and Gentiles into “one new humanity” and building them together as a holy temple.
Chapter 3: The Church as Partakers of the Promise. Paul explains the “mystery” of the gospel—that Gentiles are fellow heirs—and prays for the church to understand the depth of Christ’s love.
Chapter 4: The Church Living in Unity. Exhorts believers to walk in unity, using their diverse spiritual gifts to mature and build up the body in love.
Chapter 5: The Church as Christ’s Bride. Calls for holy living, walking in light, and compares the marriage relationship to the sacrificial love between Christ and the church.
Chapter 6: The Church as God’s Army. Outlines relationships (children/parents, servants/masters) and instructs believers to put on the “whole armor of God” to stand against spiritual forces.