Dead in Sins
means,

Spiritually dead; lost;
Without the gift of salvation;
Living a worldly life in sin;
Not born again.
But God, who is rich in mercy,
for His great love wherewith he loved us,
Even when we were dead in sins,
hath quickened us together with Christ,
(by grace ye are saved;)
And hath raised us up together,
and made us sit together
in heavenly places
in Christ Jesus...
Ephesians 2:  
4-6