Agape and logos are familiar enough to me, and if you say glosso- and ergo- are English prefixes from the Greek for speech and work, I say okay.
Aletheia is a different case. I've run into it once or twice, but considering how important the Truth is to Christian understanding of Jesus, I'm surprised it's not commonly invoked by Christians the way agape and logos are. It is the namesake for Aleteia.org, but even they merely say it's the ancient Greek word for "truth."
According to GreekBible.com, aletheia and its variants appears in about twenty verses -- nearly once per chapter -- in the Gospel According to Saint John, seventeen verses in the seven chapters of the Letters of Saint John, and half a dozen verses in Revelation.The Synoptic Gospels plus Acts use the word barely ten times. (Strong's Greek has a more complete list.)
Given that, it's little surprise that St. John gives us both
Jesus answered, “You say I am a king. For this I was born and for this I came into the world, to testify to the truth. Everyone who belongs to the truth listens to my voice.”
Pilate said to him, “What is truth?”
Can I get away here with the old stereotype of the practical-minded Roman, for whom truth is a matter of empirical fact? Empirically, Pilate could and did declare Jesus to be King of the Jews, even as he had Him crucified. The authority of Caesar is an authority to effect quite a bit of Roman-style truth.
A less Roman approach (to continue the stereotype) is to think of truth in terms of how it relates to the reality that is, rather than how reality can be made to conform to the truth Caesar asserts. The word in Greek, aletheia, is a compound of "a-," meaning "not," and "letheia," meaning "hidden." Etymologically, the very word for truth points to a reality that exists prior to, and independent of, its revelation to someone else.
Look again at that verse from 1 John. It's a command to "love... in deed and truth." The Christian's act of love is an act of truth; it reveals the One through Whom the Christian acts. This uncovering or unhiding of Jesus acting through us is a witness to the reality that the Father has commanded us to believe in the name of His Son. The Christian must reveal Christ, or the Christian is no disciple of Christ. And we all know that spoken words alone don't necessarily reveal; what is spoken of must also be shown.