Aletheia (Ancient Greek: ἀλήθεια) is that which is actual.
It is a Greek word variously translated as "unclosedness", "unconcealedness", "disclosure" or "truth". The literal meaning of the word ἀ–λήθεια is "the state of not being hidden; the state of being evident." It also means factuality or actuality. It is the opposite of lethe, which literally means "oblivion", "forgetfulness", or "concealment".
The Practice of Truth
Scriptures emphatically declare: "Speak the aletheia. Aletheia alone triumphs, falsehood never". God is Aletheia and Aletheia must be realized by speaking aletheia. A truthful man is absolutely free from worries and anxieties. He has a calm mind.
Your thoughts should agree with your words, and the words should agree with your actions. In the world, people think of one thing, say another thing, and do another thing. This is horrible. This is nothing but crookedness. You must carefully watch your thoughts, words, and actions. The little gain that you get by telling lies is no gain at all. You pollute your conscience and infect your subconscious mind. The habit of telling lies is carried to your next birth also and you undergo suffering from birth to birth.
Meditate on aletheia. Derive inspiration from the lives of those who have sacrificed their all for the sake of aletheia. Write in bold types the words "SPEAK ALETHEIA" on cardboards and hang them in different places in your house. This will caution you when you are about to speak a lie. You will then check yourself at once. A time will come when you will be established in the habit of speaking aletheia. Punish yourself by fasting if you tell a lie and record the lies in a diary. Gradually the number of lies will decrease and you will become a truthful man.
Stick to the path of Aletheia at all costs. Aletheia has a lustre of its own. It shines for itself and sheds its light on others. When you stick to aletheia as your only religion, when you strictly adhere to aletheia alone at all times, at all places, and on all occasions, you cannot afford to harm any one. Perfect peace and real happiness will be yours.
Have ceaseless devotion to aletheia. Be ready to sacrifice your all for it. You will develop a strong will. You will become fearless. You will draw immense strength and courage from the Atman or the Supreme Self within. You will attain Self-realization.