Q. 286. Do past material sins become real sins as soon as we discover their sinfulness? A. Past material sins do not become real sins as soon as we discover their sinfulness, unless we again repeat them with full knowledge and consent. Q. 287. How can we know what sins are considered mortal? A. We can know what sins are considered mortal from Holy Scripture; from the teaching of the Church, and from the writings of the Fathers and Doctors of the Church. Q. 288. Why is it wrong to judge others guilty of sin? A. It is wrong to judge others guilty of sin because we cannot know for certain that their sinful act was committed with sufficient reflection and full consent of the will. Q. 289. What sin does he commit who without sufficient reason believes another guilty of sin? A. He who without sufficient reason believes another guilty of sin commits a sin of rash judgment. Q. 290. {57} What is venial sin? A. Venial sin is a slight offense against the law of God in matters of less importance, or in matters of great importance it is an offense committed without sufficient reflection or full consent of the will. Q. 291. Can we always distinguish venial from mortal sin? A. We cannot always distinguish venial from mortal sin, and in such cases we must leave the decision to our confessor. Q. 292. Can slight offenses ever become mortal sins? A. Slight offenses can become mortal sins if we commit them through defiant contempt for God or His law; and also when they are followed by very evil consequences, which we foresee in committing them. Q. 293. {58} Which are the effects of venial sin? A. The effects of venial sin are the lessening of the love of God in our heart, the making us less worthy of His help, and the weakening of the power to resist mortal sin. Q. 294. How can we know a thought, word or deed to be sinful? A. We can know a thought, word or deed to be sinful if it, or the neglect of it, is forbidden by any law of God or of His Church, or if it is opposed to any supernatural virtue. Q. 295. {59} Which are the chief sources of sin? A. The chief sources of sin are seven: Pride, Covetousness, Lust, Anger, Gluttony, Envy, and Sloth, and they are commonly called capital sins. Q. 296. What is pride? A. Pride is an excessive love of our own ability; so that we would rather sinfully disobey than humble ourselves. Q. 297. What effect has pride on our souls? A. Pride begets in our souls sinful ambition, vainglory, presumption and hypocrisy. Q. 298. What is covetousness? A. Covetousness is an excessive desire for worldly things. Q. 299. What effect has covetousness on our souls? A. Covetousness begets in our souls unkindness, dishonesty, deceit and want of charity. Q. 300. What is lust? A. Lust is an excessive desire for the sinful pleasures forbidden by the Sixth Commandment.