Seated in heavenly places — the church as God's masterpiece, armed and united.
"For by grace are ye saved through ______; and that not of yourselves: it is the gift of God."
The whole armor of God — belt, breastplate, shoes, shield, helmet, sword — comes from Ephesians 6, likely written while Paul was chained to a Roman soldier wearing exactly that kit.
Ephesians splits neatly in half: three chapters of what God has done, three chapters of how to live because of it. Doctrine first, duty second — Paul's favorite floor plan.
Paul spent about three years in Ephesus, longer than almost anywhere — this letter went to a church he knew house by house.
The word 'walk' shows up again and again in the back half — walk in love, walk as children of light, walk circumspectly. Grace has a gait.