Confession of Sins

If we claim to be without sin, we deceive ourselves and the truth is not in us.
If we confess our sins, He is faithful and just and will forgive us our sins
and purify us from all unrighteousness.
- 1 John 1:8-9

Don't let your sins turn into bad habits.
- Mother Teresa

The confession of evil works is the first beginning of good works.
- Saint Augustine

Thou hypocrite, first cast out the beam out of thine own eye;
and then shalt thou see clearly to cast out the mote out of thy brother's eye.
- Matthew 7:5

Three conditions are necessary for Penance:
1. Contrition, which is sorrow for sin, together with a purpose of amendment;
2. Confession of sins without any omission; and
3. Satisfaction by means of good works.
- Saint Thomas Aquinas

While in a religious context, "sin" is defined as "violating God's will,"
a more universal definition might be "harming others."

Further reading: Your Own Darkness

Hypocrisy

Love One Another

Judge Not