The context is referring to believers who are the elders and leaders of their church community who are responsible for how they live before God and people. When a Christian leader slips into sin and for whatever reason continues in that lifestyle, God will bring swift judgment which can be death.
Paul was warning the church in Colossae to look out for deception by way of a good argument. In verse 3, the Scripture says…”All the treasures of wisdom and knowledge are hidden in Him.” A deceptive argument will try to establish their truth apart from the person of Jesus Christ. They will bring up topics as a way to make you doubt the divinity of Jesus Christ, salvation by faith alone in Jesus, the Trinity, and other arguments alike that will push you away from getting saved.
There are many Christians who think that they to know the Bible, but when they bring someone to Jesus for salvation, the reality is that they have been brought to a false Jesus who cannot save them.