Ephesians 2:1-3 And you has he quickened, who were dead in trespasses and sins; Wherein in time past you walked according to the course of this world, according to the prince of the power of the air, the spirit that now works in the children of disobedience: Among whom also we all had our conversation in times past in the lusts of our flesh, fulfilling the desires of the flesh and of the mind; and were by nature the children of wrath, even as others. 

‘Dead in trespasses and sins.’ There are seven dead things in Scripture: Dead, living people (2:1, 5; Matt. 8:22; 2Cor. 5:14; Col. 2:13; 1Tim. 5:6). Living, dead people (Rom. 6:2, 7-14; Col. 2:20; 3:3; 2Tim. 2:11); Dead, living bodies (Rom. 8:10). Dead bodies (Jas. 2:26; John 5:28-29). Dead works (Heb. 6:1; 9:14). Dead faith (Jas. 2:17, 20, 26). Dead sin (Rom. 7:8).

‘Trespasses’ [Greek: paraptoma] a falling aside when one should have stood upright; any deviation from the rule of duty or moral equity, as well as any flagrant offence or trespass.

‘Sins’ [Greek: harmartia] a failure to hit the mark; always in a moral sense; a sin of thought, word, or deed.

‘You walked according to the course of this world.’ Fivefold state of sinners: They walk according to the world system (2:2). The word “course” refers to the evils that run like a stream through the whole world. According to the will of satan (2:2). In the lusts of the flesh (2:3; Gal. 5:19-21; Col. 3:5-10; Rom. 1:19-32). In the lusts of the mind or spirit (2:3; 2Cor. 7:1; 1Jn. 2:15-17). By nature as children of wrath (2:3; Ps. 51:5; John 8:44; Rom. 5:12-21).

‘World’ [Greek: kosmos] world system. Translated “world” 186 times, referring to various activities of the world as organized and run by satan and man.

‘The prince of the power of the air.’ This is in reality the old man of Scripture that works in the children of disobedience (Rom. 6:6; John 8:44; 1Jn. 3:8; 5:18). Satan is the prince [Greek: archon] or ruler of the air because in this realm the evil spirits dwell, all of whom are under his dominion (2:2; 3:10; 6:11-12; Col. 2:10; 1Pet. 3:22; Rev. 12:1-17).

‘Spirit that now works’ – When one gets rid of this spirit, he no longer has the old man in him or dominates him (2:2; 4:27; 6:10-18; 1Jn. 3:8-10; 5:18; Jas. 4:7; 1Pet. 5:8-9). It only works in the children of disobedience (2Cor. 5:17-18; 1Jn. 3:8-10; 5:18; Rom. 6:14-23).

‘Children of disobedience’ – A Hebraism for people consecrated to satan and disobedience (John 17:12). The wicked one is their father (Matt. 13:38; John 8:44; 1Jn. 3:8-10; 5:18).

‘Conversation in times past’ – Manner of life (2Cor. 1:12).

‘Lusts of our flesh’ – They are listed in Galatians 5:19-21 as: Adultery, fornication, uncleanness, lasciviousness, idolatry, witchcraft, hatred, variance, emulations, wrath, strife, seditions, heresies, envying, murders, drunkenness, revelling and such like.

‘Nature the children of wrath’ – Men are sinners by nature, being born in sin (Rom. 2:14; 5:12-21; Jas. 3:6; Ps. 51:5).