Since our faith is intended to be our life and to enter into every thought and action, it is clear that it cannot be a fixed and stable thing; although it must be conveyed to us by means of definitions and formulae that are fixed and final, in the sense that they represent the best terms in human language that express, as far as it is at all possible to express, the mysteries of the revelation of God. Of course, the Catholic Church has never hesitated to declare that these definitions are always really inadequate, for it is absolutely derogatory to Almighty God to suppose that the facts of His being and life could be fitted into the limitation of human language and human thought. Hence while the Church claims that she can define as accurately as possible those mysteries of God, she does not pretend that what she has to say exhausts the subject or even represents the actual truth she is trying to teach. It is the nearest to truth that the human mind is at the moment capable of expressing. Hence there is such a thing as the development of doctrine, whereby things revealed from the beginning are found to be in the tradition of the Christian people, though they might require the rise of a heresy to make the people conscious of what had always been accepted. In this sense, therefore, it must be admitted that faith itself is a fixed and final thing, for otherwise it is clear there would be no possibility of acquiring any knowledge of the ways of God. What would be the use of dogma if it were to be constantly changed, disregarded, outgrown? Dogmatic definitions, therefore, are the vehicles by means of which the divine truths are conveyed to our minds.
Yet the real purpose of faith is something more than this. The Kingdom of God that our Lord came to establish upon earth, was not merely the elaborate or simple knowledge of the ways of God; rather it was the individual acceptance of truth simply as a means of life. God teaches me about Himself so that in the end I may be led to a closer union with Him; it is Himself for whom I am created, not for faith, but for possession. The Kingdom of God, therefore, is something that the individual from the age of reason to the end of life has to be continually realizing for himself. He has to be continually hammering away at the truths of faith, endeavouring to get more meaning out of them, to find in them the help and guidance that daily life continually demands. The whole series of mysteries will certainly be no use to me in my endless advance to God unless I try to make them my own by ceaselessly pondering over them. Of themselves they are just the bare outlines of truths, yet it is not truths but the facts that are contained in the truths that are ultimately to influence my life. Hence my first act must be to get interested in my faith. For most people it is a dull thing, connected remotely with dull Sunday afternoons, when they learnt and recited the catechism as a lesson. All that has been forgotten, and faith has now to be regarded as the revelation to us of the meaning of life, the understanding of life, the effects of life. I shall never become interested in religion until I have come to see that I must make it personal to myself - chew it, digest it, form out of it the sinews of my spiritual being.
Perhaps the reason why we think this a hard thing to do is just because we get into the habit of supposing that faith, and the attitude to life that faith ultimately produces, is something foreign to our nature. I find myself looking at this gift of God as something that is, as it were, dropt on me from outside, something external. External, indeed, those truths are, in the quite definite sense that nature left to itself would find no record of them here on earth, or at least a record so misty and incomplete as to distract rather than convince; but it is obvious that they can never influence my actions unless they have become transformed from external into internal possessions. I must so unite them to myself that they affect the whole colour of life to me. Religion may be fixed, stable, but my religion cannot be stable or fixed. The truth may be one, final, determined, but my apprehension of it can never be anything of the kind; it is changing continuously. I am always learning more and more, or forgetting the little that I once knew; the meaning grows more definite or more indistinct, but it grows always. I cannot suppose that this alone of all my forms of knowledge remains stationary all through life; and even if such a supposition ever came to me, the facts of life would very quickly disillusion me. My faith must advance or retreat, it cannot remain the same. The real trouble probably is that I look upon faith as something purely official, and only obscurely realize that there is a personal side of it as well. Now it is just here that I shall find the advantage of it to me. To be called a Catholic because we only accept certain isolated truths is hardly worth while; once I see that it is as it is called in the Scripture, a "way," then I shall find that it opens up large visions to me and reveals me to myself. Notice that the Creed mentions not merely the truth believed, but the person believing: "I believe in one God."
- text taken from Meditations for Layfolk by Father Bede Jarrett, O.P.