The opposite of it, is slackness and deficiency of faith.

 Firmness is a valued good habit. Sometimes being zealous is used instead of firmness. Indeed zeal is to insist and support some ideas, custom and traditions. The person who does this is known as zealot. So zeal is of two kinds: One of them is ardor that is in accordance with religion. It is firmness in faith, the rules of religion and it is a good attitude. The other one is zeal about false and useless customs, ideas and about the behaviors in which there are no difference to do or not to do them in respect of religion. Unfortunately many people hold fast to useless things of second type, at the same time they make the accusation of fanaticism to people who are devoted to the rules of religion and find fault for them. It is necessary to learn everything from its original source and one should see right and wrong as they are. (1)