There is only one truth everything else is only an illusion. Credibility of this statement holds true when we are talking in context of the spiritual aspect of our existence. But in the materialistic world, truth is defined on the basis of three aspects :
1. The quality or state of being true.
2. That which is true or in accordance with fact or reality.
3. A fact or belief that is accepted as true.
 
Truth, like reality, is all about perception. This means that because everyone is living in their own reality, they also have their own truths. Oftentimes, people also consider their spirituality to be their truth as well. Again, this is subjective to your reality. One person’s truth does not necessarily equal another’s. For example, if you were to take a bite of one of your favorite foods: a raw, orange carrot, your truth about carrots would be that they are tasty, orange and crisp, but does that make it true? For someone who’s colorblind and sees the carrot as grey, is their truth that carrots are grey wrong? Or, someone who hates all raw vegetables, so their truth is that carrots, while orange, are too crunchy and bland, is their truth wrong? It’s in these instances that truth can become quite a variable and is dependent on the individual’s reality.
 
Throughout history there have been three main theories about truth. The first is called the Coherence Theory. This theory is based around the idea that in order for a truth to exist for an individual, it has to align with their other beliefs. Taking the carrot example again and the idea that it is orange. In order for an individual to believe that the carrot is orange, it would have to be consistent with other items the individual believes to be orange. The color orange itself is relative to the human eye and the light spectrum that we are able to see. This is what causes truth to vary from person to person.
 
The second theory about truth is called the Correspondence Theory. This theory revolves around the idea that there are a set of absolute truths, and beliefs don’t play a role in what the truth is. For example, John F. Kennedy was elected as the 44th president of the United States of America on November 8, 1960. Now using the Correspondence Theory, regardless if someone believed this statement or not, it would still be considered the truth. Another example, there’s someone who doesn’t believe in gravity, does that mean gravity no longer exists? No! The Correspondence Theory separates truth from beliefs, which is why it is one of the most widely accepted definitions of truth.
 
The final theory prevalent throughout history is called Postmodernism. Rather than truths being aligned to beliefs like in the Coherence theory, or separate from belief altogether as with the Correspondence Theory, in Postmodernism truth is considered the product of belief. Therefore, truth is really just perception reinforced into beliefs.
 
One famous philosopher by the name of Immanuel Kant is renowned for his revolutionary distinction made between subjective experience and reality. He referred to subjective experiences as “phenomena” and reality, “noumena”. For example, the orange carrot would be considered phenomena as it only exists because of subjective experiences. Kant is clear in his teachings that humans can never truly experience noumena, as we are too trapped in our own perception of reality to experience true “reality”.
 
Ultimately, nearly all philosophers agree that truth is still subjective. Our individual experiences, beliefs and even our genetic makeup can predetermine what we believe to be true. Because of this, many people still do not believe that an “absolute truth” exists, and that it physically cannot ever exist due to our beliefs. 

In turn, this is part of the reason why so many individuals seek to reach a state of enlightenment so they can uncover the real truth and see the world as it is, through an untainted set of eyes.