Credit Card

I am not sure if it is possible for anyone to offer a conclusive viewpoint on the spiritual impact of using credit cards, since credit cards are quite new and are part of the institutional structure, as opposed to collecting interest from someone vulnerable in a person-to-person transaction.

However, at the least, having credit card debt causes a lot of stress, and having a credit card can also encourage overconsumption and spending beyond one's means, so it is good to be cautious of these things unless it is an emergency or there is no other option. No one ever not-regrets having to pay interest on a credit card.

As for interest in general, the Qur'an is quite clear about its impact. For instance: "Those who devour usury shall not rise except as one rises who is felled by the touch of Satan. That is because they say, 'Buying and selling are simply like usury,' though God has permitted buying and selling and forbidden usury. One who, after receiving counsel from his Lord, desists shall have what is past and his affair goes to God. And as for those who go back, they are the inhabitants of the Fire, abiding therein. God blights usury and causes acts of charity to grow...."(2:275-6)

In addition, it is related that Imam Ali (A) said: “The Holy Prophet (S) has cursed one who accepts interest, one who pays interest, one who buys interest, one who sells interest, one who writes the contract of interest and one who is the witness of this transaction.”