Be strong; or, strengthen yourselves; i.e. be courageous, and constant in the practice of your duty, against the devil and all his assaults. In the Lord: not in yourselves, but in the Lord Jesus Christ, in whom your strength lies, and from whom by faith you may obtain it: see Philippians 4:13 2 Timothy 2:1. And in the power of his might; or mighty power, see Ephesians 1:19: q.d. Though your own strength be but weakness, yet Christ's power is mighty, and he can communicate enough to you.
Related Commentaries of Ephesians 6:10
Ephesians 6:10
10 Finally, my brethren, be strong in the Lord, and in the power of his might.