A common rebuttal from atheists regarding their responsibility to defend their own view is to say that they simply do not have a belief. This, according to their view, absolves them from any obligation to shoulder a burden of proof. They claim that not believing God exists is substantially different from saying God does not exist.
One such atheist once explained this by using the illustration of a jar of jellybeans. He said if someone told him there were 500 jellybeans in the jar, he might not believe them. But that does not mean that he believes there are not 500 jellybeans in the jar. Therefore, this is an example of a lack of belief and is parallel to the atheist's lack of belief in God.
The problem with this illustration is, it is not parallel. The number of jellybeans in the jar does not have any implications in how a person lives his or her life. How I treat other people is not impacted by whether or not I believe there are 500 jellybeans. Even taking and eating a handful of the jellybeans is not affected by whether or not I believe there are 500 of them in the jar.
Perhaps a better analogy would be if I were to tell you that the airplane you are about to board has a faulty engine and will crash shortly after take-off. Whether or not you believe that claim is probably going to affect your behavior. If you believe the claim, you would probably not be getting on that plane (unless you have a death-wish). If you do not believe it, by getting on the plane you are, by implication, taking the position that the claim is false.
When it comes to the claim that God exists, you can choose to believe that claim or not believe it. Either way, how you live your life will reveal whether you believe that claim to be true or false. You may consciously claim to "lack a belief," but if you live as though the claim is false, you have essentially taken that position.
With this sort of claim, I would go so far as to suggest that perhaps being an agnostic is largely the same as being an atheist. In a practical sense, there seems to be no difference between the two. Both groups end up living their lives as though God does not exist. There is, as far as I can tell, no neutral ground.
We could almost view this as falling under the idea from James 14:17 where Jesus' brother makes the observation that "faith without works is dead." This covers those who profess Christ, yet live as though God doesn't exist. It also includes agnostics and atheists who live that way, as well. Also, as Jesus says in Matthew 12:30, "Whoever is not with me is against me..."
At the end of the day, our behaviors reveal a lot about our beliefs. Even if one claims to simply "lack a belief in God," they still live out their lives in a way that lines up with either an acceptance in the existence of God or a rejection of His existence. The Law of the Excluded Middle reminds us that there is not a third option. At least, not with respect to the question living our lives under the belief that God does or does not exist. You can't live as though God might exist. That does not work. We all take one position or the other. Make your choice carefully.
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