4 For he is God’s minister to you for good. But if you do evil, be afraid; for he does not bear the sword in vain; for he is God’s minister, an avenger to execute wrath on him who practices evil.
5 Therefore you must be subject, not only because of wrath but also for conscience’ sake.
minister for good — the government is for my welfare
beareth not the sword in vain — the government has the right to capital punishment and lesser judicial sentences.
avenger = one who deals justice. The word is used of God in 1 Thessalonians 4:6 — That no man go beyond and defraud his brother in any matter: because that the Lord is the avenger of all such, as we also have forewarned you and testified.
wrath (verse 5) — external. The conscience is our internal judge.
We should always view earthly relationships and situations in light of our relationship with God.