Hopefully making theology simpler to understand! (2 Corinthians 1:12)

Walk in wisdom toward outsiders, making the best use of the time. Let your speech always be gracious, seasoned with salt, so that you may know how you ought to answer each person.
Colossians 4:5‭-‬6, ESV

Do not complain about the sins of non-believers. Do not berate non-believers nor treat them with disrespect.

Show love and grace. Speak kindly, but truthfully.

And remember: treat a wayward brother as a sinner (non-believer).