God’s people are called to holiness, which involves being distinct from other people. In the OT, this is seen in the command to separate from other nations and from everything that can compromise commitment to the Lord. In the NT believers are called to distance themselves from the ways and values of the world, which can be dishonouring to God and destructive to obedience to him.
We spent the evening looking at hundreds of verses to see what we can glean from them. You can find all of those verses in the link below.