3 Keys to “Test All Things”

The Bible is the source of truth. But men have developed conflicting teachings, seemingly based on the Bible. Principles of logic can help us test for truth.

In 1 Thessalonians 5:21 we are exhorted to “test [prove, King James Version] all things; hold fast what is good.” The word translated “test” or “prove” can also mean to examine (Thayer’s Greek Lexicon). But how do we go about testing beliefs in an objective and fair-minded manner?

For those who have proved that the Bible is true, the basic answer is to compare all religious teachings with Scripture as the Bereans did (Acts 17:11).

This blog post shares several logical tests that can help us discern the biblical soundness of doctrinal arguments.

An argument, as the word is used here, is a set of statements consisting of a conclusion and reasons for that conclusion. The conclusion is what the writer or speaker decides to believe because of the reasons given.

Three ways to test an argument

1. Restate the argument clearly.

The first step is to restate the argument in your own words in a way that clearly identifies the reasoning and conclusion. This makes it easier to separately test the reasons and the conclusion.

You can do this by first analyzing the argument with the aid of the following questions:

• What is the person’s conclusion?
• What are the reasons stated and/or implied for the conclusion?

Write down the answers to the questions, stating the reasons first, then the conclusion that follows from them.

For example, consider the Pharisees’ argument found in Matthew 12:1-2: “At that time Jesus went through the grainfields on the Sabbath. And His disciples were hungry, and began to pluck heads of grain and to eat. And when the Pharisees saw it, they said to Him, ‘Look, Your disciples are doing what is not lawful to do on the Sabbath!’”

First, analyze: What was the Pharisees’ conclusion? It was that the disciples were doing something unlawful on the Sabbath. What were the reasons stated and/or implied for the conclusion? They were plucking grain on the Sabbath; doing so is working on the Sabbath, and working on the Sabbath is unlawful.

Second, restate the argument, listing the Pharisees’ reasons first, then their conclusion:

Reason 1: The disciples were plucking grain on the Sabbath.

Reason 2: Plucking grain on the Sabbath is working on the Sabbath.

Reason 3: Working on the Sabbath is unlawful.

Conclusion: The disciples were doing something unlawful on the Sabbath.

When stated in this step-by-step format, it is easier to spot the strengths and weaknesses in the Pharisees’ argument. We can note that reason 2 is not taught in the Bible. The Jews had added their own traditions and burdens to the Sabbath law (Matthew 15:9; 23:4). Picking a few grains to eat was not against God’s law, so the argument and conclusion are incorrect. (Read more about this in our article “Lord of the Sabbath: Did Jesus Christ Break the Sabbath?”)

2. Compare the statements with the standard. 

We can test for truth by comparing the statements (reasons and conclusions) with a standard of truth (in this case, the Bible). If the reasons are false, the conclusion cannot be trusted.

To illustrate, notice the following argument:

Reason 1: The Old Covenant is being superseded.

Reason 2: The 10 Commandments are the Old Covenant.

Conclusion: The 10 Commandments are being superseded.

In this example, the first reason is true (see Hebrews 8:13), but the second reason is false. The 10 Commandments were around before the Old Covenant and continued in the New Testament. (If you are unsure of these facts, read our articles “Were the 10 Commandments Around Before Moses?” and “Are the 10 Commandments Upheld in the New Testament?”) The fault with the covenant was not with the law, but with the people (Hebrews 8:8).

Since reason 2 is false, the conclusion is also false.

We should be careful to note any attempt to present generalizations, theories, informed guesses or outright speculation as absolute truth. A highly probable conclusion can be tentatively accepted with the understanding that it is speculation and may have to be revised if additional evidence comes to light.

3. Make sure that words are correctly used and understood.

Any word or phrase in the argument that has a wrong or unclear meaning can lead to a conclusion that is totally false, partially false or simply uncertain.

We can use the following two scales to test the accuracy and clarity of the meaning of words used in an argument:

1. Test for correctness of meaning. Are the uses of the words totally wrong, partially wrong or correct? In addition to checking the meanings of the English words, it can be good to check the meanings of the original biblical words. A meaning that is correct in the context used passes this test.
2. Test for clarity of meaning. Are the uses of the words meaningless, vague or ambiguous? Or do they have one clear meaning? A word used with one clear meaning passes this test.

To illustrate, consider the following argument:

Reason 1: All who believe in the Lord Jesus Christ are saved.

Reason 2: John believes in the Lord Jesus Christ.

Conclusion: John is saved.

In this argument, the words believe and saved can mean different things to different people.

If they use believe to mean “faith without keeping the commandments” and if they use saved to mean “finally saved,” then the conclusion would be false according to the Bible.

On the other hand, if we use biblical definitions, we understand that believe can mean “faith demonstrated by works” and saved can mean “saved from past sins.” Using these biblical definitions, the conclusion would be true. (For more on the biblical meaning of belief and salvation, read our articles “What Is Faith?” “Epistle of Straw—or a Book of Faith?” and “What Does It Mean to Be Saved?”)

Watch out if the meaning of terms is either partly or totally incorrect or partly or totally unclear! Then the conclusion should not be trusted.

Using logic to avoid fallacies

You can see from the above sample arguments how convoluted, entangled and tricky arguments can be. Taking the time to prayerfully apply such logical tests when studying doctrine can go a long way toward avoiding being trapped by inaccurate or deceptive teachings.

For more about biblical truth, read “What Is Truth?” “What Is Doctrine?” and “How Do We Know the Bible Is True?”