Covet, in a good way, means, "eager to obtain"
(a good thing... such as wisdom, spiritual gifts, etc.). (1 Cor. 12:31)

Covet, in a bad way, means, "to want greedily; or to desire an unlawful thing"; idolatry. (Col. 3:5)

Mortify therefore your members which are upon the earth; fornication, uncleanness, inordinate affection, evil concupiscence, and covetousness, which is idolatry...
Colossians 3:5