Matthew uses the word, "aletheia" only once in his entire gospel, and even then it is more correctly translated "honesty". [22:16].
Mark uses the word only three times.
Luke writes "aletheia" twice and "alethos" three times. In each case, the word means "certainty".
John, however, uses "alethos" twice and "aletheia" no less than twenty-five times! In all twenty-seven, the word means, "truth".
As far as John, the Beloved Disciple, and his editor, John, the Elder, are concerned, "Truth" is possibly the most important concept in the entire Bible.
Yet I have been a Christian for over 70 years, attended thousands of church services -- Catholic, Protestant, Fundamentalist and Pentecostal -- and never once have I heard a sermon or listened to a discussion on "Truth".
In my own translation of John's Good News in my book, "MARK and JOHN: The First and Last Gospels", I have taken care to transmit the Beloved Disciple's words as accurately as possible, Here is Jesus teaching in the temple (page 95):
The Festival of Tabernacles was already nearly over. It was the last day, the principal day of the Festival [called “The Great Hosanna”], when Jesus went into the temple and began to teach. The leading citizens were astonished and said to each other, “How did this man acquire such learning and insight when he has had no training?”
“My teaching is not Mine,” Jesus answered, “but the words of Him who sent Me. Whoever wishes to obey God, will know in his heart whether My teaching proceeds from God or whether I speak on My own authority. The man who speaks on his own authority, seeks his own personal glory. [Therefore anything he says may either be true or false]. But the Man who desires to give all the glory to God, is perfectly sincere; and there is no deceit in Him at all.”
“Isn’t this the man the chief priests and Pharisees want to kill?” the leading citizens murmured. “Yet here he is right in the temple speaking freely, and there they are, all standing around [listening to him] and saying nothing. Perhaps our leaders have now decided this man really is the Messiah? But we all know this man comes from Nazareth. And when the Messiah really arrives, He will have no birthplace at all.”
Jesus heard what they were saying. “Yes, you all know Me!” He shouted out. “And you all know My home town! Yet I don’t come here of My own accord or on My own authority. He who sent Me is Truth itself; and Him you do not know. I know Him because I come from Him and He sent Me. I am the Light of the world. Whoever follows Me will not walk in darkness, but will be accompanied by the Light of Life.”