But we do have record that the cross' title was written in Hebrew, Latin, and Greek.
God certainly had a special plan for these languages: the language of God's Law, the language of human power, and the language of human wisdom. The presence of His name in all three languages left the situation unambiguous to whoever might have been in the area to read it. Jesus of Nazareth, King of the Jews, hung on that cross. When pressed about it, Pilate would not amend those words.
In this way, though maybe unnecessary thanks to the Gift of Tongues the Holy Spirit later gave to His apostles, the sign stood as a kind of Rosetta Stone, which no one could misunderstand. It shows that history itself, along with all human matters, belong completely to Him, and at the same time it made those languages new by virtue of that single title, grounding them firmly in the Truth Himself.
Latin and Greek, themselves originally vernaculars, continue to hold a special place in their respective churches, both Catholic and Orthodox. Syriac, a dialect of Aramaic, continues to be used in many Eastern churches as well, again Catholic and Orthodox both. All three constitute especially venerable traditions—and to this we may add Coptic, since Jesus spent his early years in Egypt; Slavonic, for its very writing system's role in the conversion of the Slavs; and a handful of others I am more or less ignorant of. With each one, by entering into the language, you enter the mind of those first converts, who themselves entered the Mind of Christ.
In the Latin Catholic Church (that is, the Latin Rite of the Roman Catholic Church, or however you want to name it) we call the Latin language a "sacramental"—the same sort of thing as holy water, something which conveys grace to those who use it with an openness to those graces.
Demons hate it because of its legal precision, by which, in the name of the same Christ named in Latin on the cross, they are driven out of people, things, and places, fulfilling Christ's own prediction that His followers would cast out demons.
By forming one's faith life around one of these languages, one can more clearly ask those basic human questions that Christ is the answer to, without having to deal with the centuries of semantic drift and overloading that are scattered about the minefields of our modern vernaculars. The vernacular, of course, is no impediment to personal prayer, but as more and more people are gathered in one place the confusion of Babel threatens to set in.
On the other hand, every little Latin grammatical lesson, every new piece of vocabulary learned, reveals new wonders and opens the door to the great body of literature that was composed in the single Mind of Christ.
But we had this, and in the 20th century we let it slip through our fingers, not knowing what we'd been given. The problem is not that we don't know Latin. The problem is that, in broad cultural strokes, even when we did, we didn't care.