Sin

When we are born the sin nature is already in us we don't have to teach other's to do wrong. We can see from God's word how horrible sin is!

2 Timothy 3:1~4
But understand this, that in the last days difficult times will come. 2 For people will be lovers of themselves, lovers of money, boastful, arrogant, blasphemers, disobedient to parents, ungrateful, unholy, 3 unloving, irreconcilable, slanderers, without self-control, savage, opposed to what is good, 4 treacherous, reckless, conceited, loving pleasure rather than loving God

Isaiah 44:19,20
No one thinks to himself,
nor do they comprehend or understand and say to themselves:
‘I burned half of it in the fire—
yes, I baked bread over the coals;
I roasted meat and ate it.
With the rest of it should I make a disgusting idol?
Should I bow down to dry wood?’
20 He feeds on ashes;
his deceived mind misleads him.
He cannot rescue himself,
nor does he say, ‘Is this not a false god I hold in my right hand?’