Are credit cards wrong for Christians?

The straight answer

Scripture says nothing about plastic, and quite a lot about what a carried balance does to you. Those are two different questions and they get answered differently.

Used as a payment method and cleared every month, a credit card is a tool: no interest, no servitude, and, in the United States, better fraud protection than a debit card. Nothing in Scripture forbids that.

Used as a source of money you do not have, it is the sharpest modern example of the thing Proverbs describes: the borrower is servant to the lender. At typical card rates a revolving balance is designed so the minimum payment mostly pays interest, which is why people carry one for years without the number moving much. Proverbs also warns about the person in a hurry: haste tends toward want, and a card removes the wait that would otherwise force the decision.

The honest test is not whether you own a card but whether you can name your balance right now and whether it was zero last month. If the answer is yes and yes, you are using a tool. If not, treat it the way Scripture treats debt: urgently, with a written payoff plan, and without shame. The trap is common because it is well designed.