931. The commandment of internal belief is brought before one for the first time, either of one’s whole life or for the first time after loss of faith, as follows:
(a) It is brought before a person for the first time in his life, when he first hears the truths of faith, or first realizes his duty of accepting them. Examples: A Catholic child who has just reached the age of reason and has been told in Sunday school that he must believe the Creed and other truths he has been taught; an adult Catholic who hears for the first time of transubstantiation, or of some other dogma just defined by the Church; a non-Catholic who has just perceived the truth of the Catholic Church.
(b) The commandment of internal belief is brought before one for the first time after loss of faith, as soon as the duty of returning to belief occurs to the mind.
932. Does this commandment require that, as soon as the obligation of faith dawns on one, one is obliged without an instant’s delay to make a formal and explicit act of faith?
(a) As regards children, on account of the imperfection of their understanding, it can easily happen that they do not perceive that the obligation binds them there and then, or that it binds under sin, and thus some time may elapse after the use of reason, or after knowledge of the command of faith, before the omission of the act of belief would become a sin. Practically every child of Catholic education complies with the command when, having learned the truths that must be known, he says devoutly the act of faith, either in his own words or according to the form given in the Catechism.
(b) As regards adults, while the entrance of converts into the Church admits of some delay for necessary preparation, the act of faith itself should not be postponed for an instant, once the necessity of making it is perceived as certain.
933. As to its frequency or the times when the act of faith should be renewed, there are various opinions, but in actual life the question presents no difficulty.
(a) As to theory, the theologians are divided, some holding that the act of faith should be made at least once a year, others holding for once a month, still others for all Sundays and holydays. There is no solid support for any of these opinions, and it seems that the time and frequency of acts of faith are not determined by divine law.
(b) As to practice, the theologians agree that one who fulfills the usual religious duties of a Catholic, has also fulfilled the command to renew the act of faith. Thus, those who attend Mass and receive the Sacraments, as the law of the Church prescribes, make acts of faith in doing so, which satisfy the divine law of faith.
934. Those who omit to make an act of faith in time of temptation against faith, are also guilty of sin, if the omission is through sinful neglect.