For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.  John 3:16

Verily, verily, I say unto you, He that heareth my word, and believeth on him that sent me, hath everlasting life, and shall not come into condemnation; but is passed from death unto life.  John 5:24

Who shall not receive manifold more in this present time, and in the world to come life everlasting. Luke 18:30

He that believeth on the Son hath everlasting life: and he that believeth not the Son shall not see life; but the wrath of God abideth on him.      John 3:36

Verily, verily, I say unto you, He that believeth on me hath everlasting life. John 6:47

And these shall go away into everlasting punishment: but the righteous into life eternal. Matthew 25:46

What is everlasting life, life eternal, or life everlasting?  It is life that never ends.  Can you lose everlasting life?  If you can lose everlasting life then it is not everlasting and it is not from the God of the Bible.

What kind of life do you have?  If you can lose it, it is not everlasting.  If you lost it, then you never truly had everlasting life to begin with.

…let the word of Christ dwell (take up its life in you) richly…

Note:  If you believed that you could not lose your salvation when you became a Christian, but changed your mind based on someone’s teaching, then you were simply taught incorrectly.  If, when you became saved, you believed that you could lose your salvation, then you have never been truly saved.  God the Father, through His Son Jesus Christ, only grants believers life that is everlasting .