NET

4 because it is God’s servant for your well-being. But be afraid if you do wrong because government does not bear the sword for nothing. It is God’s servant to administer punishment on the person who does wrong.

Darby

4 for it is God's minister to thee for good. But if thou practisest evil, fear; for it bears not the sword in vain; for it is God's minister, an avenger for wrath to him that does evil.

KJV

4 For he is the minister of God to thee for good. But if thou do that which is evil, be afraid; for he beareth not the sword in vain: for he is the minister of God, a revenger to [execute] wrath upon him that doeth evil.

Strong's

4 For ^G1063 he is^G2076 the minister^G1249 of God^G2316 to thee^G4671 for^G1519 good^G18. But^G1161 if^G1437 thou do^G4160 that which is evil^G2556, be afraid^G5399; for^G1063 he beareth^G5409 not^G3756 the sword^G3162 in vain^G1500: for^G1063 he is^G2076 the minister^G1249 of God^G2316, a revenger^G1558 to execute wrath^G3709 upon^G1519 him that doeth^G4238 evil^G2556.