§ 1814 Faith is the theological virtue by which we believe in God and believe all that he has said and revealed to us, and that Holy Church proposes for our belief, because he is truth itself. By faith man freely commits his entire self to God. For this reason the believer seeks to know and do God’s will. The righteous shall live by faith. Living faith works through charity.
§ 1815 The gift of faith remains in one who has not sinned against it. But faith apart from works is dead. When it is deprived of hope and love, faith does not fully unite the believer to Christ and does not make him a living member of his Body.
§ 1816 The disciple of Christ must not only keep the faith and live on it, but also profess it, confidently bear witness to it, and spread it: All however must be prepared to confess Christ before men and to follow him along the way of the Cross, amidst the persecutions which the Church never lacks. Service of and witness to the faith are necessary for salvation: “So every one who acknowledges me before men, I also will acknowledge before my Father who is in heaven; but whoever denies me before men, I also will deny before my Father who is in heaven.”
Pope Francis speaks on Christian faith in Lumen Fidei as a light shining in the darkness. § 1 “The light of Faith: this is how the Church’s tradition speaks of the great gift brought by Jesus. In John’s Gospel, Christ says of himself: “I have come as light into the world, that whoever believes in me may not remain in darkness” (Jn 12:46). Saint Paul uses the same image: “God who said ‘Let light shine out of darkness,’ has shone in our hearts” (2 Cor 4:6). § 15 “Abraham rejoiced that he would see my day; he saw it and was glad” (Jn 8:56). According to these words of Jesus, Abraham’s faith pointed to him; in some sense it foresaw his mystery. So Saint Augustine understood it when he stated that the patriarchs were saved by faith, not faith in Christ who had come but in Christ who was yet to come, a faith pressing towards the future of Jesus.
Faith, “The assurance of things hoped for, the conviction of things not seen” Heb 11:1, is our firm belief in God and all that he has revealed to us through Holy Mother Church. “When you received the word of God which you heard from us, you accepted it not as the word of men but as what it really is, the word of God” 1 Thes 2:13. Faith resides in our intellect; we believe because God is all-knowing (cannot be deceived) and all-good (cannot deceive), so what He tells us is infallibly true. Our faith must be constant; the shaliakh Rabbi T’oma gave Rabbi Yeshua three years of faithful service, but we remember him for his one moment of doubt Jn 20:25. Our faith must be complete. We completely submit our intellect and will to God. Our faith therefore illuminates our daily life. Our fallen race inherits from its first parents a propensity to sin, but our constant objective must be to live as Holy Mother Church teaches. We seek to live by the theological and cardinal virtues. We consciously avoid the seven capital sins. We go to the Holy Sacrifice of the Mass every day if possible, or every Sunday at minimum. We go to Confession every week if possible, or every month at minimum. We do all this because we have faith that the Catholic Church has Rabbi Yeshua‘s authority to teach us how to prepare for heaven. Our faith is a free assent to the whole truth that God has revealed. We have faith only if we believe in Rabbi Yeshua‘s entire public revelation. The Catholic faith is faith that Rabbi Yeshua instituted a divine institution, a Church blessed with authority to infallibly teach his public revelation. If we accept only doctrines consistent with our own experience we are not accepting them on faith but rather on human analysis.