dear friend. read 1 john 5:9-12. if we say eternal life can be lost it makes God a liar. that is a serious offense.
This is an interpretation of what it means to be saved.
I would suggest many think they know God but are just thought believers and have not
become cleansed heart and righteous action believers, or even believing God can achieve
this in them.
We are saved by faith, which cleanses and purifies our heart which is shown in our behaviour.
If our hearts are not purified then our faith has failed and our behaviour will be as sinful as before.
