Finally, be strong in the Lord and in the strength of His might.
The word “finally” should get your attention. It means that we have arrived at the concluding thought of the section, or in this case, the book itself. Paul is essentially saying, “After all that I have told you, there is one last thing… one concluding thought that I must share with you.”
Charles Spurgeon once said that, “Satan never kicks a dead horse.” Once you have applied, by faith, the contents of Ephesians 1:1—6:9, you are no longer a “dead horse” to our enemy. You have become an active target on his radar screen. He can’t take your salvation (John 10:28), but he can sabotage your story. So what are you to do? First and foremost: be strong in the Lord and in the strength of His might.
Consider all that He has done for you… the fact that you have become His child… that you now play a part in His great and glorious plan… that He is maturing you and growing you… that He has filled you with His Spirit… that He has given you His Word… that He has placed you into His Body! When you understand those great and glorious truths then you will KNOW that you have more than enough ABILITY to BE STRONG!
So fear not, Christian. Although you have an adversary, your ally is exceedingly more than enough to guarantee your victory.