A. Original sin is not the only kind of sin; there is another kind of sin, which we commit ourselves, called actual sin.
Q. 52. What is actual sin?
A. Actual sin is any wilful thought, word, deed or omission contrary to the law of God.
Q. 53. How many kinds of actual sin are there?
A. There are two kinds of actual sin--mortal and venial.
Q. 54. What is mortal sin?
A. Mortal sin is a grievous offense against the law of God.
Q. 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. 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.