The double negative "will not go unpunished" is used for emphasis. This can be stated in active form. Alternate translation: "God will certainly punish the one who gets rich quickly" (See: [[rc://en/ta/man/translate/figs-litotes]] and [[rc://en/ta/man/translate/figs-activepassive]])
The implied information is that this person gains wealth by unfaithful or dishonest means. Alternate translation: "the one who tries to get rich quickly" (See: [[rc://en/ta/man/translate/figs-explicit]])