What is happening here is that the Once Saved, Always Saved doctrine keeps people stuck in the flesh, only having a "positional" spirit/born again status with God. So many of them (in my estimation) are still in the flesh, not in the spirit. They truly are, in a sense, defeated in the fight against sin. It's the attitude of, "Just give up". Surrender to sin. Not implying this is the case with every OSAS follower, but it seems that way. They forever remain in the condition of the one who wants to do right, but does the evil he hates.
This is why verses saying that, believers cannot sin, are beyond comprehension to them. It must mean something else.
And the one verse saying, if we sin we have an advocate, is magnified exceedingly and must mean what it says plainly.
But as then he that was born after the flesh persecuted him that was born after the Spirit, even so it is now (Galatians 4:29).