Man is born into sin, and is open rebellion to God as Psalm 53 declares!
Mankind regardless of his opinion of God whether He exist or not, has a debt owed to God, not in financial debt but in moral obedience to Him.
God starts every human being born into Adam’s sin nature, not in a state of innocence as Adam and Eve once were.
If a man continues in the sin until he dies, will be forever separated from the love of God and will pay for his sin in hell.
However, once man is born from the Spirit of God (Jesus pays the debt of sin), as John 3 speaks of a new birth, man now has two natures dwelling inside of him.
An inner battle to please God in obedience and a battle to please his own Adamic sin nature.
That’s the prelude into this song, War of Spirit and Flesh!