Every religion, philosophy, or worldview makes truth-claims.  Whether you turn to a Buddhist, a Muslim, a Hindu, a Christian, a pagan, or even a secular humanist atheist, he or she will attempt to offer truth-claims or explanations for our experience of the world and our experience of ourselves.  And while there certainly is some common ground of belief shared by all worldviews, there are also some pretty significant disagreements on what is claimed to be true.  And these worldview disagreements are usually about weighty matters as well—matters such as the existence and nature of God, the human soul, the nature of right living, the explanation of evil, the goal of human life, life after death, and so on.

With so many truth-claims being made on so many issues of such magnitude, we might feel overwhelmed.  How do we judge between these worldview truth-claims?  How can we test whether or not something is worthy of belief?  I’d suggest that there are three basic tests which we can employ to investigate and scrutinize the truth-claims made by all worldviews.

POPULAR REASONS WHY PEOPLE BELIEVE
Before we take a look at what I think are the three essential tests for evaluating any truth-claims, let’s briefly look at some popular, but less than stellar reasons often used by people to test whether or not something is true—the claim and then a response:

1. Instinct — “It seems true to me.” 
    To this statement we must simply ask . . .
    . . . Why?  What is guiding one’s instinctual ability to judge between competing truth-claims?
2. Feelings — “I like the feeling I get.” or “It feels right.” 
    . . . Can feelings be mistaken?
3. Wish fulfillment — “The God that I (want to) believe in would never send someone to hell.” 
    . . . Maybe not, but the God one wants to believe in may not be the God who actually exists.  We can never determine objective truth simply by what we want to be true.
4. Custom — “This is the way I / my family / my culture has always been.” 
    . . . Can they be mistaken?  What if one came from a Nazi background?
5. Popularity contest — “Well, ‘everyone’ believes it.” 
    . . . Again, can ‘everyone’ be wrong?  Counting noses is never a good means of determining truth.
6. Pragmatism — “It works for me, therefore it must be true.” 
    . . . However, almost anything can ‘work’ for a time.  Truth works overall.  For instance, a belief may ‘work’ at ridding oneself of guilt by denying it rather than absolving it.
7. Significance — “It gives my life meaning.” 
    . . . Is the meaning simply the result of wish-fulfillment or is it connected with reality?

Obviously, all of the above reasons for believing something to be true seem deficient and not the best tests to determine whether or not a truth-claim is really true (although, #s 6 & 7 do seem to be better candidates that #s 1-5).  Nevertheless, I think there are three criterion for testing truth-claims which, when used together, offer us the best chances of determining true beliefs.  Here they are.

1.  Internal Coherence — This is a test for rational consistency.  This asks if a belief makes sense?  We need to determine whether beliefs are rationally consistent within themselves and in relation to others beliefs of one’s larger worldview.  Some beliefs are known to be self-referentially inconsistent, or self-defeating.  An example might be the belief that all “knowledge” is scientific knowledge.  This is obviously self-defeating because the belief itself is not a scientific statement.  Therefore, the belief dies by its own standard for knowledge.  Another way a belief can fail this test is when two beliefs are in contradiction with each other, meaning that at least one of the beliefs must be false.  So, we must ask if the beliefs hold together?  For example, if a person is a Naturalist (believing that human life is accidental, random, and without ultimate purpose), he cannot then introduce the belief that we have an objective moral obligation to treat another person justly or with kindness. 

Now, while the internal coherence test is essential for determining if something is true, it is not sufficient.  That is, consistency alone does not determine truth.  Consider this example: If Hillary Clinton is President, Bill Clinton is the First Man.  Hillary Clinton is President.  Therefore Bill Clinton is the First Man.  This argument is completely coherent and consistent.  However, it’s not true.  So, we need to add other criterion to the internal coherence test.

2.  External Correspondence — This test asks if a belief fits the facts of reality.   Does it correspond to the real world?  Proposed truth-claims must have explanatory power, or the ability to give account for our experience of the world (whether it be history, science, psychology, human nature, etc.).  For instance, a worldview can be tested by its ability to explain cosmological questions like the origin of the universe; anthropological questions like the existence of minds and free will; moral questions like the existence of evil and our experience with guilt.     

Further, the explanatory power of truth-claims should (a) be comprehensive in scope—able to explain more or better than alternative theories; (b) have predictive power—suggesting new evidence and problems; (c) have precision—accounting for more details; (d) be illuminating—integrating otherwise unrelated data; (e) avoid ad hoc hypotheses—functioning only to explain away counter-evidence; (f) be simple—not needlessly multiplying the basic concepts, assumptions, and principles of an explanation.

3.  Functional Adequacy — This tests the livability of a truth-claim as a belief.  Is it a viable belief “on the street”?  Does it work in real life?  Some views sound good on paper, but are proven false in the laboratory of life.  Consider an eastern guru who asserts that the physical world is an illusion, yet he still looks both ways before crossing the street.  A person cannot live out such an illusory belief of the world for very long (or he’ll be hit by a bus before long!).  Even more than that, a belief system must integrate one’s life.  It must incorporate and meet the deepest human needs.

SUMMARY
In evaluating the truth or falsity of  propositions/truth-claims/beliefs, we must be sure to always look for three things: internal coherence (the logical), external correspondence (the factual), and functional adequacy (the livable).  For a belief to be true it must be meaningful, it must line up with the real world, and it must not only help us survive in daily life, but allow us to flourish.  Consequently, these are also the three areas in which our thinking can and does go wrong: logic, facts, and values.