Τοῦ λοιποῦ, ἐνδυναμοῦσθε ἐν κυρίῳ καὶ ἐν τῷ κράτει τῆς ἰσχύος αὐτοῦ. Of the rest, be strong in the Lord and in the power of his might.
Paul signals a new section with Τοῦ λοιποῦ. Does this phrase mean “of the rest,” “henceforth,” or “finally”? Since Paul is not talking about time, it cannot be “henceforth.” Since Paul is not referring to a remaining group of people, it cannot be “of the rest.” However, for it to be “finally,” it is typically in the accusative case. Aside from Eph. 6:10, the genitive form only occurs in one other place, Galatians 6:17, where it is understood temporally (“henceforth”). However, the accusative and genitive forms can be understood to be synonymous phrases, and, therefore, we can translate it as “finally” in this context, albeit a rare instance. Paul is introducing a conclusion to his letter. He tells his readers and listeners to be strong in the Lord and in the power of his might. Christians do not draw on themselves for strength, but to God. The verb, ἐνδυναμοῦσθε, “be strong,” could be middle or passive. If it is passive, then the phrase might be translated, “Finally, be strengthened in the Lord and the power of his might.” In this way, the Lord and his mighty strength is seen as the sphere from which believers are strengthened. If it is middle, it might read, “Finally, strengthen yourselves in the Lord and in the power of his might.” In this case, believers are said to be the ones to strengthen themselves in the Lord and his mighty strength. However, Ephesians places an emphasis on God equipping the believers with power (3:16), so it is best to see ἐνδυναμοῦσθε as a passive. It is not Christians who supply or equip themselves with strength, but rather, God equips them.
Finally, be strong in the Lord and in the power of his might.
Are you trying to walk the spiritual walk and live the Christian life by your own strength? You do not have to do it by your own strength. In fact, God will provide for you all the strength you need. Christ came in the flesh, lived, died, and rose again. The very power that equipped him to sacrificially love you is accessible to you to live out your faith in a pleasing way to God. You need only to allow God to equip you! He gives his Spirit to his children in order that they might be strengthened. Being a Christian is not about living a good or righteous life by one’s own will. Rather, it is about Christ making it possible on your behalf to live a life that God declares to be righteous and by God making it possible for you to begin to live out a righteous life through the help of the Spirit. As a Christian, you do not do it alone. You do it with God’s helping hand. Allow him to equip you. And if you are already a Christian, realize that you have been equipped. Tap into God’s mighty power and so live a righteous life as the Lord himself is righteous.