Aletheia is the Greek word for truth. Its form suggests the unhidden or the unconcealed — reality brought into the light, as opposed to what is false, veiled, or merely apparent. In John's Gospel especially, aletheia is not just correct information but reality as God sees it, and ultimately a Person: Jesus says I am the way, the truth, and the life.
Truth in the Bible is something you do and walk in, not only something you know: he that doeth truth cometh to the light. It liberates — ye shall know the truth, and the truth shall make you free — and it sanctifies, for Jesus prays, sanctify them through thy truth: thy word is truth. To love aletheia is to love reality as it actually is under God, and to refuse the comfortable lie.
Aletheia in Scripture
And ye shall know the truth, and the truth shall make you free.