The Security of the Believer is in CHRIST, not one's self. If a person could lose their salvation by doing bad deeds, then, logic would dictate that they can gain it back by their good deeds as well, and this is a salvation by man made works, and NOT the GRACE of GOD! Who or what can pluck us from the Father's hand? No one and nothing (John 10:28-29). Who or what can separate us from the love Christ? Nothing (Romans 8). When does a child of GOD become unborn? How long is Eternal Life? Is it until you commit the first sin? IF a person is said to have lost/walked away from/given up their salvation, then, we have to ask our selves: Was that person ever saved to begin with? Salvation is by GOD' GRACE!