From Pope Benedict XVI’s encyclical Caritas in Veritate (2009):
Through this close link with truth, charity can be recognized as an authentic expression of humanity and as an element of fundamental importance in human relations, including those of a public nature. Only in truth does charity shine forth, only in truth can charity be authentically lived. Truth is the light that gives meaning and value to charity. That light is both the light of reason and the light of faith, through which the intellect attains to the natural and supernatural truth of charity: it grasps its meaning as gift, acceptance, and communion. Without truth, charity degenerates into sentimentality. Love becomes an empty shell, to be filled in an arbitrary way. In a culture without truth, this is the fatal risk facing love. It falls prey to contingent subjective emotions and opinions, the word “love” is abused and distorted, to the point where it comes to mean the opposite. Truth frees charity from the constraints of an emotionalism that deprives it of relational and social content, and of a fideism that deprives it of human and universal breathing-space. In the truth, charity reflects the personal yet public dimension of faith in the God of the Bible, who is both Agápe and Lógos: Charity and Truth, Love and Word.
Because it is filled with truth, charity can be understood in the abundance of its values, it can be shared and communicated. Truth, in fact, is lógos which creates diá-logos, and hence communication and communion. Truth, by enabling men and women to let go of their subjective opinions and impressions, allows them to move beyond cultural and historical limitations and to come together in the assessment of the value and substance of things. Truth opens and unites our minds in the lógos of love: this is the Christian proclamation and testimony of charity. In the present social and cultural context, where there is a widespread tendency to relativize truth, practising charity in truth helps people to understand that adhering to the values of Christianity is not merely useful but essential for building a good society and for true integral human development. A Christianity of charity without truth would be more or less interchangeable with a pool of good sentiments, helpful for social cohesion, but of little relevance. In other words, there would no longer be any real place for God in the world. Without truth, charity is confined to a narrow field devoid of relations. It is excluded from the plans and processes of promoting human development of universal range, in dialogue between knowledge and praxis.
— Caritas in Veritate 3-4