Sinful Nature Or Theological Teaching?

When Paul writes about behavioral issues in the Church, is it because of their sinful nature or because their theology was wrong?

Behavioral vs Doctrinal and how they support each other when mirror-reading

Many New Testament epistles have a section where doctrinal issues addressed, and then later in the epistle, behavioral issues are addressed.  We can use this to validate mirror-reading.  In other words, if we mirror-read and discover the false teaching that Paul was responding to, we can then extrapolate that out to what types of behavior that false teaching would produce.  If we find that behavior as one of the behaviors that Paul discusses in the latter part of the epistle, then we can take that as validation of our mirror-reading of the false teaching.

This could have theological implications.  For example, when Paul, in Ephesians says "Children, obey your parents", are we to take it that Paul has nothing better to address than to remind the Church of a common ethic?   Or was there perhaps a false teaching that gave those children (who could be adult children) a reason to disobey their parents?  This could have an impact on what we use to support the idea of a "sinful nature".  If you're curious of my theological views of "the flesh", check out this episode of the RE2 Podcast.