I used to respond to these sorts of sentiments with dismissive slogans and nerdy references like "crappy catechesis" or "Christ in the Eucharist is the True Bread from which we will no longer hunger" or "Americanization of Catholics" or "Robert Bellah's Sheilaism," etc. Now I realize how I had it all wrong. The more honest I am with myself, the more I have to agree that this line sadly but aptly describes my experience of the modern church ever since I converted.
Not that I deny or reject the content of any of these slogans or concepts. But I have come to realize they do not speak for themselves or stand alone apart from the human person. Christian truth is not a slogan or a proposition existing in some alternate Platonic realm of ideas or even in some "mind of God" separate from our reality. The truth that sets us free and truly heals us is found in this reality, in persons who are personally in Christ, in those who personally partake in Christ from within the heart. The truth comes from the inner being of a man, so it's just as much the vibe, energy, aura, subtext, and emotion we give off as it is in the content of the ideas or words we communicate. As the Fathers implied, the truth is enhypostatic.
So I disagree when I hear Catholicons quip, after they've privately and with self-congratulatory pomp thrashed the arguments and sentiments of non-Catholicons, "I'm being a bastard, but it's the truth..." It's as if St. Jerome and Chesterton at their most pugnacious have become the model of Catholic orthodoxy.
There really can be no separation between the ideas or words we profess and who we are as persons in Christ. If I am a cruel or arrogant man or speak in a cruel or arrogant manner, all the doctrinal orthodoxy I profess intellectually alone is rendered null and void. If the demons can know and speak the truth about Christ, then perhaps I should be more careful with my grip of the truth of Christ lest I join their ranks.
So when Christ says "I am the Truth," it means we abide in the truth only to the extent we are personally dying Christ's death in order to live Christ's life, not just ritually (often confused for sacramentally) but actually. If we act in an un-Christlike way, that's not just another forgivable offense or charming foible (moralistic attitude towards sin). We're not just being "who we are" with all our imperfections which God loves anyway because His Son paid the debt already (quasi-heretical Christology). To act in a un-Christlike way may be unavoidable in this valley of tears, but it is NOT human, or more precisely, it's not humanizing or masculating. When we do so, we're choosing to live outside of Christ. We're turning against our true nature which is Christ. We're inclining ourselves towards Death. I am betraying myself, for my identity does not begin with ME in some pre-graced state outside of Christ. My true identity IS Christ Himself and Christ in me. Yet we hear so much psychotherapeutic identity talk among Catholics, which is partly Rahner and the Jesuits' great achievement and which is why I almost always leave Mass starving these days.