WASHINGTON, DC (Catholic Online) - "I don't want you hanging around that group any longer!" This was a comment I heard from my parents more than once when I was growing up.

"Why? What's wrong with them?" I'd blurt back.

"They are not a good influence on you. I don't like how you act after you've been around them for awhile."

My parents were right in protecting me from influences that would be harmful as my heart and mind were maturing and my young conscience was being formed. When there is not a sufficient moral framework established we can become vulnerable to dangerous influences.

"Beware the leaven of the Pharisees." (Lk 12:1) Our Lord offered a similar warning in today's gospel regarding those whose influence would move us away from God's heart. He never was hesitant to warn his followers about the dangers of this hypocritical and dangerous group.

The Pharisees were a significant faction of religious leaders who exercised great influence. As Jesus pointed out in the previous chapter of Luke's gospel, they were more interested in exteriors, maintaining the façade of religion while the interior life is not addressed.

The Lord said to him, "Oh you Pharisees! Although you cleanse the outside of the cup and the dish, inside you are filled with plunder and evil." (Lk 11:39) That was their main focus, enforcing conformity to the laws no matter what the heart may be like.

He likens them to leaven that causes bread to rise. Leaven affects the way that the loaf comes out.

The influence of those who hypocritically deceive and drive people away from the truth of Christ and the teachings of the Church is still very much a problem today.

One particular area of deadly influence comes from Catholics in public life, such as government, the entertainment industry, etc. They may identify themselves as a part of the One, Holy, Catholic and Apostolic Church but then present ideas and ideals that are at odds with that identity.

Their prominence leads to a dual scandal. First, they are living lives of personal hypocrisy, but then, even more at issue, they have an impact on others, swaying them to embrace the same error. They are leavening the loaf.

In truth, all of us are capable of being influenced. In fact, influence and formation from an external source is critical to our development as Catholic Christians and the proper formation of conscience. The key question, however, is who do you trust?

Obviously, the answer is not to trust anyone who simply says they are Catholic. Attending the same liturgy is not the basis of authentic unity and trust.

The Catholic Catechism gives us a clearer answer. "The criterion that assures unity amid the diversity of liturgical traditions is fidelity to apostolic Tradition, i.e., the communion in the faith and the sacraments received from the apostles, a communion that is both signified and guaranteed by apostolic succession." (CCC, 1209)

In 1988, Blessed John Paul II wrote "Christifideles laici" (Christ's Faithful People), after the 1987 Synod of Bishops, in which he looked at the mission of Christ's people in the world. One of his main areas of focus involved the "Criteria for Ecclesiality," in other words, how do you know which group or individual can be trusted.

In this section of the document he listed several criteria that can help determine trustworthiness. Here, I've distilled them down into three key areas: their call to holiness, their profession of faith and their commitment to evangelization.

The Call to Holiness

Blessed John Paul II wrote, "It is always called to be more of an instrument leading to holiness in the Church, through fostering and promoting 'a more intimate unity between the everyday life of its members and their faith."

In other words, does the message that this person or group brings lead me closer to Christ and His Church or move me father away? Do I find myself becoming a more faithful Catholic or not?

Faithfulness in this context is not just about our intellectual alignment with truth but our love. Do we find ourselves falling more and more in love with God and our neighbor - thus fulfilling Christ's two great commandments?

Fr. Hans Urs von Balthasar once wrote, "Faith means the fundamental response to the love that has offered itself up for me." Faith, then, is more than following the rules, but rather coming to a point of deeper relationship with the one who is the ruler.

Profession of Faith

Profession of faith involves "The responsibility of professing the Catholic faith, embracing and proclaiming the truth about Christ, the Church and humanity, in obedience to the Church's Magisterium, as the Church interprets it. For this reason every association of the lay faithful must be a forum where the faith is proclaimed as well as taught in its total content."

Here ...