We are urged to be kind to other people and to treat them with respect. While these are good and praiseworthy virtues to practice, before we can consistently perform them, we need to cultivate them in our hearts.
St. Paul of the Cross comments on this reality in a letter featured by the Church’s Office of Readings.
[B]e constant in practicing every virtue, and especially in imitating the patience of our dear Jesus, for this is the summit of pure love. Live in such a way that all may know that you bear outwardly as well as inwardly the image of Christ crucified, the model of all gentleness and mercy. For if a man is united inwardly with the Son of the living God, he also bears his likeness outwardly by his continual practice of heroic goodness, and especially through a patience reinforced by courage, which does not complain either secretly or in public. Conceal yourselves in Jesus crucified, and hope for nothing except that all men be thoroughly converted to his will.
If we want to be truly good and holy people, we need to first unite ourselvesinwardlyto Jesus Christ.
Otherwise, our outward actions may end up being empty, and we will likely not have the strength to endure.
Being kind to others is not easy, and our frail human nature will inevitably fail if we rely only on our own strength. Instead, we should be fed with the strength of our Lord and let him work through us.