“Finally, my brethren, be strong in the Lord, and in the power of his might. – Ephesians 6:10

In order to understand and grasp the magnitude of the importance of this verse one must observe how important the word “finally” is here.  It is taken from the Greek phrase tou loipou meaning in conclusion or in summation.  It is also a phrase that “depicts something so extremely important that it is placed at the very end of the letter.  This way if the reader remembers nothing else in the letter, he will be more likely to remember this one thing.” (p.68, Sparkling Gems from the Greek) 

The verses after Ephesians 6:10 describe the Armor of God.  However, it is everything that is mentioned prior to this in the book of Ephesians that makes you appreciate this passage more. 

“The book of Ephesians contains some of the deepest theological teaching in the New Testament.
§  The election of the saints (Ephesians 1:4)
§  The predestination work of God (Ephesians 1:5)
§  The adoption of the sons of God (Ephesians 1:5)
§  The dispensation of the fullness of times (Ephesians 1:10)
§  The sealing of the Holy Spirit (Ephesians 1:13)
§  The earnest of the Holy Spirit (Ephesians 1:14)
§  The power of God that is available to every believer (Ephesians 1:19)
§  The grace of God (Ephesians 2:1-10)
§  The eternal plan of God (Ephesians 3:10-11)
§  The fivefold ministry gifts (Ephesians 4:11-13)
§  The infilling with the Spirit (Ephesians 5:18-19)
§  And the list goes on…” (p.68, Sparkling Gems From the Greek)

Notice that in previous letters to other churches and in the previous chapters to this very church in Ephesus, Paul instructs the believer on ways to live the victorious Christian life.  However, this largest church of its day took the information down but seemed not to apply much of it.  Therefore, two things came about – (1) the devil still worked effectively among the members there and (2) it warranted the focus of what came after “finally” in Ephesians 6:10 – the Armor of God or a teaching on spiritual warfare.

So, that is why Paul said, “Finally…”.  Just in case the believer is Ephesus did not recall anything else in the previous chapters, Paul wanted them to remember that they must have these spiritual weapons to keep the devil at bay.
Are you suited with His “Helmet of Salvation”, “Breastplate of Righteousness”, “Belt of Truth”, “Shoes of Peace”, “Shield of Faith”, and “Sword of the Spirit”?  Know the function of each one and pray for the application to your spiritual body each day.  And be watchful for the "finallys" in Scripture.