John said we can KNOW we have eternal life,
You forgot to read the rest of the book
1 John 2:3 And hereby we do know that we know him, if we keep his commandments. 4. He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him.
Is it possible to be saved and not know God?
1 John 3:14- We know that we have passed from death unto life, because we love the brethren. He that loveth not
his brother abideth in death.
Has a person who does not love the brethren passed from death to life?
1 John 3:18-19- My little children, let us not love in word, neither in tongue; but in deed and in truth.
And hereby we know that we are of the truth, and shall assure our hearts before him.
I think it will trust john whom said our life is forever, no matter what. And this is the basis of me conti uing to believe
The key word is BASIS. The basis for our keeping God's commandments, and loving the brethren, and loving God, and bearing fruit, is not to obtain eternal life, nor is it to retain eternal life, the basis is because WE HAVE ETERNAL LIFE. In other words, if you have eternal life, there will be fruit and love and obedience, albeit not perfection.