READ THE BOOK!
It's not works; but FAITH.
(Now we'll get the folks that claim that 'faith' is a 'work'!)
Everlasting existence bequeathed to the undeserving but continuously faith-exercising confessing soul is without end, no matter what.
On the other hand, if one says that he believes, but continues to lead a carnal life-style without change, then it is he that is the liar, not the Jesus of the Bible.
And the one insisting that you can lose your salvation--and with it eternal life with God--s the perpetrator of a false gospel that cannot utterly remove the guilt of one's sin.
Correct. He that exercises a saving faith possesses the irreversible gift of God, and cannot lose his salvation.
If one has to do something more to keep the gift than just to gratefully accept it, that would necessarily be a works-based "salvation" which would be no salvation at all. And it would be another gospel about another christ.
Read the Book. 2 Cor. 11:3-4