The very meaning of salvation is ETERNAL SECURITY having received ETERNAL LIFE.
"SHALL" MEANS WITHOUT THE SHADOW OF A DOUBT
I am the door: by me if any man enter in, he shall be saved, and shall go in and out, and find pasture. (Jn 10:9)
LIFE WITH CHRIST IS ETERNAL AND ABUNDANT
The thief cometh not, but for to steal, and to kill, and to destroy: I am come that they might have life, and that they might have it more abundantly. (Jn 10:10)
THE GOOD SHEPHERD KNOWS HIS SHEEP AND DOES NOT LOSE THEM
I am the good shepherd, and know my sheep, and am known of mine...
My sheep hear my voice, and I know them, and they follow me:
(Jn 10:14,27)
CHRIST'S SHEEP RECEIVE ETERNAL LIFE AND SHALL NEVER PERISH
And I give unto them eternal life; and they shall never perish... (Jn 10:28a)
NO ONE CAN PLUCK CHRIST'S SHEEP FROM HIS HAND OR THE FATHER'S HAND
...neither shall any man pluck them out of my hand. My Father, which gave them me, is greater than all; and no man is able to pluck them out of my Father's hand. (Jn 10:28b,29)
Note: This is all about genuine children of God -- Christ's sheep. Eternal life is GOD'S GIFT to the one who repents and believes.