the self-deception and delusion is believing one can be sinless in the flesh. no one can.
This is where different ideas about what it means to walk blamelessly before the Lord come
in.
Paul expected people who are called to walk righteously, day in day out.
Paul appears to talk about obvious sin, which can be resolved and deeper issues of the heart,
which only God sees and will judge at the appropriate time.
There is a large difference between defeat, and just not seeing evil and we are called to shun
this, and just walking like the world and say this is acceptable behaviour.
There will always be mysteries, for instance Judas walked among the disciples but they only
knew he was lost when he betrayed Christ.
What is obviously wrong is people aware of sin in their lives and just accepting this as normal.
For if you live according to the flesh, you will die; but if by the Spirit you put to death the misdeeds of the body, you will live.
Rom 8:13
so God gave them over to a depraved mind, so that they do what ought not to be done.
Rom 1:28
Set your minds on things above, not on earthly things.
col 3:2
For
God did not
call us to be impure, but
to live a holy life.
1 Thess 4:7