In the Catholic tradition, we have the terms regula fidei, sensus fidei, and analogia fidei. Translated, they mean, "the rule of faith," the "sense of faith for a person," and "the analogy of faith." In practical terms, what do these ideas mean for the Catholic Christian?
If faith were a purely personal matter, if we were individuals, unrelated and separated, who personally believed in some “god,” then every individual believer would be free to make up their own faith as they saw fit. They could change the tenets of their faith whenever they felt the need, and they would never have to give an account of what they believed or why, nor would they feel the need to explain their beliefs to another. They would never feel the need to relate their beliefs to another person. In fact, such a situation would make relationships exceedingly difficult.
It is, however, part of our human nature to develop relationships. We are social creatures, not lone individuals, but creatures that long to be with each other and that find joy in companionship and relationship. Our relationship with each other is based on dialog, with intimate communication that reveals and accepts from one to another. As created beings, we are made in the image and likeness of our Creator who, while in a wholly different category of being than ours, did in the very act of creating us impart within us an openness to hear the Word of His revelation. Therefore God initiates a relationship with us, a necessity dictated by the very nature of God as a being wholly other than us and beyond our ability to perceive or perfectly comprehend. As created beings, we are created to recognize the truth of God’s revelation. We have a God-given, ability to sense and grasp the meaning of God’s revelation, especially the revelation of God given in the Gospel message of Jesus Christ. In practical terms, when we hear the Gospel with an open mind and heart, we sense that there is more here than myth or fable or story. The truth of the message speaks to the truth that God has placed in our being, and truth knows truth; it recognizes itself and responds. Our response is faith. We believe.
But we are not simply individual believers in the Gospel. The revelation of God calls us together. In calling us together, God has formed us as a community: the Church. We are a community of believers, gathered together by the Gospel message, focused on the Gospel message, and working to proclaim the Gospel message. And as believers in God, as a community founded by His revelation and for His revelation, our community has a rule. But it is not a rule like some might expect. Our rule is not like the worldly rules that merely govern specific behaviors, that allow and deny certain actions, or that determine where you may go or not go. The rule of faith is an expression of what we share as a community. The rule of faith is at the very heart of what makes us a community, for what we share as a community is an experience of God’s revelation of Himself to us. Therefore, as a community formed by God and centered on His revelation, we likewise have been gifted with the ability to sense and grasp the meaning of God’s revelation. The community exercises this ability as a whole, doing corporately and simultaneously what the individual believer does in the presence of God’s revelation.
Our experience of God is a revelation of love and truth. As a result of that shared experience, of God revealed as love and truth, we recognize that we must take care that what we proclaim about God is true, and that it cannot contradict itself – truth cannot be opposed to truth, nor can love be opposed to love. All that we say about God must be in harmony with the truth that God has revealed to us in Sacred Scripture and in our Sacred Traditions. Being in harmony means that as we live our faith in community, we each express the gifts and abilities that God has given us. Though we have many gifts, the gifts work together for the community in order to help build up the community and to further the work of the community. Likewise, the various elements of the faith are interrelated. They work reciprocally so that no one element negates another or attempts to falsify any other element of the faith.
In the Catholic Church, that community formed by the experience of God-love-truth, we hold the Scriptures and Sacred Tradition as the exposition of the shared experience of the revelation of God. Our community hands on what it has received in the revelatory experience of God-love-truth. The teachings that we have received, in Scripture and in Tradition, reveal a consistency within themselves, a “pattern of teaching” (Rom 6:17). Over time, our community has reflected on the truth it has received. As a result of these reflections, the members of the community, exercising the gifts of the Holy Spirit, may propose developments to the understanding of the faith. These developments are always accepted or rejected on the basis of the rule of faith which we have received, understanding that God, as revealed truth, will never contradict or oppose Himself. Therefore, any proposition that does not hold fast to the rule of our faith is categorically rejected.