1 Corinthians 5:1

It is actually reported that there is immorality among you, and immorality such as is unknown even among pagans ??that a man has taken his father's wife!

James 1:6-8

Only, let him ask in faith, with never a doubt; for the doubtful man is like surge of the sea whirled and swayed by the wind;

2 Peter 3:16

speaking of this as he has done in all his letters ??letters containing some knotty points, which ignorant and unsteady souls twist (as they do the rest of the scriptures) to their own destruction.

Treasury of Scripture Knowledge

Summary

Unstable as water, thou shalt not excel; because thou wentest up to thy father's bed; then defiledst thou it: he went up to my couch.

Bible References

Unstable

James 1:6
Only, let him ask in faith, with never a doubt; for the doubtful man is like surge of the sea whirled and swayed by the wind;
2 Peter 3:16
speaking of this as he has done in all his letters ??letters containing some knotty points, which ignorant and unsteady souls twist (as they do the rest of the scriptures) to their own destruction.

Because

1 Corinthians 5:1
It is actually reported that there is immorality among you, and immorality such as is unknown even among pagans ??that a man has taken his father's wife!