Yes, one must remain in Christ. We are recipients of eternal life as long as we are in him. Calvinist confuse this also, by claiming it's not possible to Fall away.
I started a post one day of what does it mean to be In Christ......and passage that comes to me as of now is the communion....what does it mean to eat his flesh and drink his blood or you shall not have no part with me?
If any man be in Christ He is a new creation .
It may be too possible that Christ is all one needs for their eternal destiny....
Maybe that's what it means to barely escape the flames of fire....idk
Because there are those who may have boldness to stand...yet some when He comes may not have boldness at all...what shall happen?
I have a feeling that somewhere....maybe in the greek....there are terms like Both "eternal life and life eternal in the bible.....
As there are holy ghost and holy spirit , kingdom of God and kingdom of heavens,
JESUS Christ and Christ Jesus....the and Thou.... in and of.......Jacob and Israel
Abram and abraham....etc
Why, because even though one of the 2 means eternal life...the quality of life in this life.....that may be likely a facet of the Life eternal......or vise versa...I have to figure out where I can find scrip like that since I do not know Greek.
Since eternal life scripturally means to know the only true God and Jesus whom He has sent....[dont quote me]
And to know someone is part of the close relationship ....of doing what the other wants. Yes to share in ones life would mean to remain Into/in Them....[i like that]