Different Religions, which one is correct?

(from gotquestions.org)
There is no doubt that the number of different religions in the world makes it a challenge to know which one is correct. First, let’s consider some thoughts on the overall subject and then look at how one might approach the topic in a manner that can actually get to a right conclusion about God. The challenge of different answers to a particular issue is not unique to the topic of religion. For example, you can sit 100 math students down, give them a complex problem to solve, and it is likely that many will get the answer wrong. But does this mean that a correct answer does not exist? Not at all. Those who get the answer wrong simply need to be shown their error and know the techniques necessary to arrive at the correct answer.

How do we arrive at the truth about God? We use a systematic methodology that is designed to separate truth from error by using various tests for truth, with the end result being a set of right conclusions. Can you imagine the end results a scientist would arrive at if he went into the lab and just started mixing things together with no rhyme or reason? Or if a physician just started treating a patient with random medicines in the hope of making him well? Neither the scientist nor the physician takes this approach; instead, they use systematic methods that are methodical, logical, evidential, and proven to yield the right end result.

This being the case, why think theology—the study of God—should be any different? Why believe it can be approached in a haphazard and undisciplined way and still yield right conclusions? Unfortunately, this is the approach many take, and this is one of the reasons why so many religions exist. That said, we now return to the question of how to reach truthful conclusions about God. What systematic approach should be used? First, we need to establish a framework for testing various truth claims, and then we need a roadmap to follow to reach a right conclusion. Here is a good framework to use:

1. Logical consistency—the claims of a belief system must logically cohere to each other and not contradict in any way. As an example, the end goal of Buddhism is to rid oneself of all desires. Yet, one must have a desire to rid oneself of all desires, which is a contradictory and illogical principle.

2. Empirical adequacy—is there evidence to support the belief system (whether the evidence is rational, externally evidential, etc.)? Naturally, it is only right to want proof for important claims being made so the assertions can be verified. For example, Mormons teach that Jesus lived in North America. Yet there is absolutely no proof, archaeological or otherwise, to support such a claim.

3. Existential relevancy—the belief system must conform to reality as we know it, and it must make a meaningful difference in the life of the adherent. Deism, for example, claims that God just threw the spinning world into the universe and does not interact with those who live on it. How does such a belief impact someone in a day-to-day manner? In short, it does not.