You might not have considered yourself to be dead before your conversion to the Way of Christ, but you were, spiritually speaking. All of us who have sinned against God could be said to be spiritually dead. In Romans 6:23, Paul said, "The wages of sin is death."
When we add those Christian characteristics of faith, virtue, knowledge, self-control, perseverance, godliness, kindness, and love, we add the "divine nature" to our lives. These are the very things that make up life.