Jamieson, Fausset & Brown

Finally, be strong in the Lord and in His mighty power.

“Most of the oldest manuscripts for "finally," read, "henceforward," or "from henceforth" (Ga 6:17). be strong--Greek, "be strengthened." in the power of his might--Christ's might: as in Eph 1:19, it is the Father's might.”

Put on the full armor of God, so that you can make your stand against the devil’s schemes.

“An image readily suggested by the Roman armory, Paul being now in Rome. Repeated emphatically, Eph 6:13.”

For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this world’s darkness, and against the spiritual forces of evil…

“Greek, "For our wrestling ('the wrestling' in which we are engaged) is not against flesh," &c. Flesh and blood foes are Satan's mere tools, the real foe lurking behind them is Satan himself, with whom our conflict is.”

Therefore take up the full armor of God, so that when the day of evil comes, you will be able to stand your ground, and having done everything, to stand.

“We must have our armor always on, to be ready against the evil day which may come at any moment, the war being perpetual (Ps 41:1, Margin). done all--rather, "accomplished all things," namely, necessary to the fight, and becoming a good soldier.”

In addition to all this, take up the shield of faith, with which you can extinguish all the flaming arrows of the evil one.

“Above all--rather, "Over all"; so as to cover all that has been put on before. Three integuments are specified, the breastplate, girdle, and shoes; two defenses, the helmet and shield; and two offensive weapons, the sword and the spear (prayer).”

for which I am an ambassador in chains. Pray that I may proclaim it fearlessly, as I should.

“For--Greek, as in Eph 6:19, "On behalf of which." an ambassador in bonds--a paradox. Ambassadors were held inviolable by the law of nations, and could not, without outrage to every sacred right, be put in chains. Yet Christ's "ambassador is in a chain!"”

Tychicus, the beloved brother and faithful servant in the Lord, will tell you everything, so that you also may know about me and what I am doing.

“Tychicus--an Asiatic, and so a fit messenger bearing the respective Epistles to Ephesus and Colosse (Ac 20:4; 2Ti 4:12). a beloved brother--Greek, "the beloved brother"; the same epithet as in Col 4:7. minister--that is, servant. in the Lord--in the Lord's work.”

Grace to all who love our Lord Jesus Christ with an undying love.

“Contrast the malediction on all who love Him not (1Co 16:22). in sincerity--Greek, "in incorruption," that is, not as English Version, but "with an immortal (constant) love" [WAHL]. Compare "that which is not corruptible" (1Pe 3:4).”