There are two types of sin:
Actual sin is any wilful thought, word, deed or omission contrary to the law of God.
Venial sin is a slight offence against the law of God in matters of less importance or in matters of great importance. It is an offence committed without sufficient reflection or full consent of the will.
Mortal sin is a grevious offence against the law of God as it deprives us of spiritual life and brings everlasting death and damnation on the soul.
A sin is mortal when it is a grevious matter with sufficient reflection and full consent of the will.
Original Sin- The story of the Fall
The Serpent asked the woman 'Did God really tell you not to eat the fruit from that tree?'
The woman replied 'We may eat fruit from trees in the garden but we may not touch or eat the fruit from the tree in the middle or we will die.'
The serpent said 'You will certainly not die, for God knows that when you eat from it your eyes will be opened and you will know good from evil.'
So the woman ate some of the fruit, she gave some to her husband, who also ate it. Then their eyes were opened and, realizing that they were naked, they sewed fig trees together for clothes.
They hid from the LORD God as he walked through the garden but he called out to the man.
The man told God that he hid because he was naked.
God replied, 'Who told you that you were naked? Have you eaten from the forbidden tree?'
The man admitted, 'The woman you put me with, she gave me some fruit and I ate it.'
Then the LORD God said to the woman, 'What is this you have done?'
The woman said 'The Serpent deceived me, and I ate.'
The LORD God cursed the Serpent to eat dust.
He made the woman's pains in childbirth very painful.
And he banished the man from the garden to eat thorns from the field.
Seven Deadly Sins
LUST- To have an intense desire for something (usually sexual).
GLUTTONY- Excess in eating and drinking (not to be confused with greed)
GREED- Excessive or reprehensible acquisitiveness (being greedy)
SLOTH (Laziness)- Disinclined to activity or exertion: not energetic or vigorous.
WRATH- Strong vengeful anger or indignation
ENVY- Painful or resentful awareness of an advantage enjoyed by another joined with desire to possess the same advantage.
PRIDE- Quality or state of being proud- inordinate self-esteem.