One's lifestyle reflects what's in the heart. It's NOT that anyone is saved BY their deeds, but that their deeds are a sign of what's in the heart; of one who has humbly surrendered to Jesus as Lord, or not.
Natural man values physical things (e.g., life) over eternal (e.g., salvation). A believer in Christ values eternal life and the Kingdom of God over all else. (1Ki 3:5-14; 1Jn 2:15-17)