[Elsie]

17 Ye therefore, beloved, seeing ye know these things before, beware lest ye also, being led away with the error of the wicked, fall from your own stedfastness.

'Tis amazing how many folks miss this verse.

[aMorePerfectUnion]

2 Peter 3:17 : The possibility of loss of salvation is not in view, but loss of steadfastness is.

The danger was false teachers, like that Falseworld religion.

Best

[af_vet_1981]

Tis amazing how many folks miss this verse.

One explanation for the one who does what you point out is that is he effectively believes he is saved by believing he is saved, ignoring or denying his own behavior. On the opposite side, we have our witness Job, one of the three men (although there is a fourth in my reading) called tam/perfect in the scriptures.

Job 13:15-16
King James Version

15 Though he slay me, yet will I trust in him: but I will maintain mine own ways before him.
16 He also shall be my salvation: for an hypocrite shall not come before him.

The maintenance of a godly way is necessary and can be summed up in the two greatest commandments.