And you were dead in the trespasses and sins in which you once walked, following the course of this world, following the prince of the power of the air, the spirit that is now at work in the sons of disobedience—
Before I came to faith in Christ, even though I was a child, I was still spiritually a zombie. I was a dead man walking. That is what Paul teaches in this passage. I must believe what this scripture says. Nobody, not even me, is born good. We are born spiritually dead in sin. And we walk in that sin, marching mindlessly toward hell.
The passage says that the dead zombie souls of our unredeemed natures will mindlessly follow two things: 1) the path of this world, and 2) the spirit of this world, Satan. That ain't good! We are on a path away from God at the start of our lives. We are dead men walking.
We are set on a road to hell in our sin. It is the only course we know, the "course of this world". We are oriented in the direction away from God by our sin. This life is lived outside of Christ in what scripture calls our "present evil age" (see Galatians 1:4). We can't change that fact about ourselves by ourselves. Our only hope is through the regeneration Christ brings. He sets us free, makes us alive, and places us on His "path of life".
We will also follow Satan's bidding in our unredeemed state. Usually not overtly, since I have yet to meet any overt Satanists, but in covert operations, Satan is THE influence in the world system AND in the individual lives of walking dead sinners. Jesus said Satan is like a father to sinners. And in following sin, we ultimately follow Satan's evil, disruptive, destructive, disobedient schemes.
These two tendencies toward the world and toward the devil are why we desperately need to believe that Jesus died for our sins and gives us new life. It is why I am thankful that He saved me when I trusted in that truth. It is why I must be passionate to live and proclaim the gospel of His saving life!