Youcat commented through CCC – Question n. 347.

YOUCAT Question n. 347 - Why is “not practicing what you preach” such a serious deficiency in a Christian?

(Youcat answer) Agreement between one’s life and one’s witness is the first requirement for proclaiming the Gospel. Not practicing what you profess is therefore hypocrisy, a betrayal of the Christian duty to be “salt of the earth” and “light of the world”.  

 A deepening through CCC

(CCC 2044) The fidelity of the baptized is a primordial condition for the proclamation of the Gospel and for the Church's mission in the world. In order that the message of salvation can show the power of its truth and radiance before men, it must be authenticated by the witness of the life of Christians. "The witness of a Christian life and good works done in a supernatural spirit have great power to draw men to the faith and to God" (AA 6 § 2).       

Reflecting and meditating 

(Youcat comment) Paul was the one who reminded the Church in Corinth: “You show that you are a letter from Christ… written not with ink but with the Spirit of the living God, not on tablets of stone but on tablets of human hearts” (2 Cor 3:3). Christians themselves, not the things they say, are Christ’s “letters of recommendation” (2 Cor 3:2) to the world. It is all the more devastating, therefore, when there are even priests and religious who abuse children. They not only commit unspeakable crimes against their victims. They deprive many people of hope in God and extinguish the light of faith in quite a few souls.

(CCC Comment)

(CCC 2045) Because they are members of the Body whose Head is Christ  (Cf. Eph 1:22), Christians contribute to building up the Church by the constancy of their convictions and their moral lives. The Church increases, grows, and develops through the holiness of her faithful, until "we all attain to the unity of the faith and of the knowledge of the Son of God, to mature manhood, to the measure of the stature of the fullness of Christ" (Eph 4:13; cf. LG 39). (CCC 2046) By living with the mind of Christ, Christians hasten the coming of the Reign of God, "a kingdom of justice, love, and peace" (Roman Missal, Preface of Christ the King). They do not, for all that, abandon their earthly tasks; faithful to their master, they fulfill them with uprightness, patience, and love.   

(The next question is:  “Teacher, what must I do to have eternal life?” (Mt 19:16)