“Being born again, not of corruptible seed, but of incorruptible, by the word of God, which liveth and abideth for ever.”  
1Peter 1:23

He says we were born again by incorruptible seed.
The word ‘incorruptible’ is from the Greek ‘aphthartos’ which can be rendered ‘undecaying, immortal’.
This is one difference between the Christian and the unbeliever, the unbeliever is born of corruptible seed; he can easily be affected by external factors unto corruption, he is mortal; can lose his life at any given time, there is no assurance of security for him, in short:
“…having no hope, and without God in the world:”  Ephesians 2:12
But when he gets born again, things change, that corruptible seed is supplanted by incorruptible seed, all of the things that could affect him unto death become ineffective and useless:
“…Jesus Christ, who hath abolished death, and hath brought life and immortality to light through the gospel:”  2Timothy 1:10
He ceases to function in the realm of death and darkness, things have changed- inside he is a totally new, different and uncommon person and his position in life changes; he can live life confidently, fulfilling purpose with joy, knowing that:
“…nothing shall by any means hurt you.”  Luke 10:19