Dear Brian,

Thanks for the very good question.

My colleagues can probably give a more simplified answer but allow me to share what the Catechism says on this issue. Because of the length of the text, I have provided an outline of the important portions along with a link to where you can read it. Just click on the Next graphic at the bottom of each page to read the next article for each given chapter.

I recommend you read both sections, in context, so you can get a solid answer to your question. The first chapter of Section One answers the essence of your question though the third chapter in the same section talks about the natural law, which is important to acknowledge.

Basically, the natural law is that thing inside us that tells us something is very wrong or very right, without someone else telling us it is very wrong or very right.

I hope this helps,

Mike

Part Three - Life In Christ

Section One: Man's Vocation: Life In The Spirit

Chapter One: The Dignity Of The Human Person

Article 1: Man: The Image Of God

In Brief

Article 2: Our Vocation To Beatitude

1. The Beatitudes
2. Human Freedom in the Economy of Salvation

In Brief

Article 3: Man's Freedom

1. Freedom and Responsibility
2. The Desire for Happiness
3. Christian Beatitude

In Brief

Article 4: The Morality Of Human Acts

1. The Sources of Morality
2. Good Acts and Evil Acts

In Brief

Article 5: The Morality Of The Passions

1. Passions
2. Passions and Moral Life

In Brief

Article 6: Moral Conscience

1. The Judgement of Conscience
2. The Formation of Conscience
3. To Choose in Accord with Conscience
4. Erroneous Judgement

In Brief

Chapter Three: God's Salvation: Law And Grace

Article 1: The Moral Law

1. The Natural Moral Law
2. The Old Law
3. The New Law or the Law of the Gospel

In Brief

If you are hungry for more, you can always get a cheap copy of the Catechism of the Catholic Church on-line.

I hope this helps,

Mike

Dear Brian,

Thanks for asking such an important question.

As the Catechism states, sin is any deliberate thought, word, deed, or omission that contradicts the will of God and right reason.

Conscience is meant to be an indicator of right and wrong but we have a responsibility to form our own consciences according to what is objectively true and good. Before this formation we are very prone to:

• the whims of our disordered desires
• the wayward disobedience of the world (i.e. our culture), and
• the snares of the devil.

Since the Word of God comes to us through Scripture and Tradition, infallibly taught through the Magisterium of the Church, foolproof means of knowing the objective truth of the moral law are found in the Church's moral teachings which can be found in the Catechism and the Bible.

Since the formation of our conscience is a process that includes learning what the Church officially teaches on human behavior and why, the virtue of prudence helps us along the way.

Pray, think, and do not go against your conscience — even if everyone else say something's okay and tries to pressure you into accepting it. Have the courage to please God rather then man.

When you are on God's side you're always in the majority.

Peace,

Paul