That this section is distinct from the five that precede it is evident from two facts. Paul introduced it differently, and the emphasis in it is on God"s resources. Earlier Paul urged the strengthening and growth of the body of Christ ( Ephesians 4:12; Ephesians 4:16). Now he explained the need for this. The body is at war with a spiritual enemy. We do not just walk, but we also war. [source][source][source]
"These two responsibilities (home and work on the one hand, and spiritual combat on the other) are quite different from each other. Husband and wife, parents and children, masters and servants are visible, tangible human beings, while the "principalities and powers" arrayed against us are invisible, intangible demonic beings." [1][source]
"Sooner or later every believer discovers that the Christian life is a battleground, not a playground, and that he faces an enemy who is much stronger than he Isaiah -apart from the Lord." [2][source]
"The image of the cosmic struggle or confrontation with evil is frequent in the book, but it hits its high point here ( Ephesians 1:19-23; Ephesians 2:1-7; Ephesians 4:7-10; Ephesians 5:7-14; Ephesians 5:17)." [3][source]
According to the Book of Acts and other sources, there was an unusual amount of demonic activity in Ephesus, and Paul encountered it when he ministered there (cf. Acts 19:13-20). [4] It was, therefore, appropriate that he addressed this subject at some length in this letter to the Ephesians. [source][source][source]