Sin is an offense against
reason,
truth,
and right conscience.
It is a failure
in genuine love for
God and neighbor
caused by a
perverse attachment to certain goods.
It wounds the nature of man
and injures human solidarity.
It has been defined as
an utterance, a deed, or a desire contrary to the eternal law.
Sin is an offense against God:
"Against you, you alone,
have I sinned, and done
that which is evil in your sight."
Sin sets itself
against God's love for us
and turns our hearts away from it.
Like the first sin,
it is disobedience,
a revolt against God
through the will to become "like gods,"
Sin is thus
"love of oneself even to contempt of God."
In this proud self-exaltation,
sin is diametrically opposed
to the obedience of Jesus,
which achieves our salvation.
Catechism of the Catholic Church