The following is an excerpt from STR Enhanced Solid Ground July 2012 by Greg Koukl. 

• "Either Jesus is not God or God is not a trinity. "
  

This is a failure of equivocation, but the problem is difficult for most to see at first. It has to do with the troublesome word, “is.” There are at least five meanings for the word “is.”

Resolving the equivocation in this argument requires distinguishing between the “is” of essential predication (“Aristotle is human”) and the “is” of identity (“Aristotle is the author of the Nichomachean Ethics”). There are also the parts/whole “is” (“Aristotle is skin and bones”), the “is” of accidental predication (“Aristotle is white”), and the “is” of existence (“Aristotle is”). 

When Christianity teaches that Jesus is God, it doesn’t mean that Jesus and God are exactly identical. Jesus is different from the Father. He shares the Father’s essential nature, but He is not everything that God is. God subsists in three persons; Jesus is only one of those persons.

• “Jesus is God. Mary is the mother of Jesus. Therefore, Mary is the mother of God.”

The form here seems correct—the conclusion follows from the premises. It also seems that the individual statements are true. But something’s wrong here. God is not the kind of being that has a mother. Where did we go wrong?

The problem becomes more obvious when we take it a step further: “Mary is the mother of God. God is a trinity. Therefore, Mary is the mother of the Trinity.” This, of course, is patently false. But why is there a problem if the form is sound and the claims are in order?

The trouble lies with the terms. There’s an equivocation here on the clause “Jesus is God” in the first syllogism. Jesus is a very unusual individual. Yes, He is God, but He’s also fully human. Jesus is one person with two natures, the nature of God and the nature of man.

When we say Jesus is God, we are not saying His humanity is divine. That would be a contradiction. We are saying He is God in that He has a divine nature. Mary is the mother Jesus in the sense that she’s the mother of His humanity. She is the mother
of His human nature, not His divine nature.

Equivocation—lack of clarity—on these terms makes a false conclusion seem sound. The claims are right. The form is right. But the conclusion is false because the meanings of the terms are equivocal.


Page 5 of STR's July 2012 issue of Solid Ground - http://www.str.org/site/DocServer/Enhanced_Solid_Ground_July_2012.pdf?docID=6382&autologin=true 

Q. What evidence would cause an "atheist" to be swayed to a faith-based worldview?

A. I was an atheist for much of my life, starting in high school. In fact, a while back I was contacted by a nurse who had been a classmate of mine at Prospect High School in suburban Chicago during the late 1960s. She recalled how she had been "the good Catholic girl," while I was the acerbic atheist who was constantly belittling her for her faith. She was stunned when she stumbled upon one of my books and discovered I had later become a Christian!

I think your question may reflect a misunderstanding about faith. When I was an atheist, I still had a "faith-based worldview" - it was a faith built on my unproven conclusion that God does not exist. We all take steps of faith each day of our lives. Let me explain.

I define faith as being a step we take in the same direction we believe the evidence is pointing. For instance, I'm sitting here at my computer while sipping a bottle of water. How did I know the water wasn't poisoned? Well, the bottle came sealed. It bears the label of a reputable water company. It looks clear. There was no odor coming from the bottle when I opened it. My wife gave it to me, and she has no reason to want to harm me. So based on that evidence, it made sense to take a step of faith in the same direction and take a sip. Did I know for an absolute fact that it wasn't poisoned? No, but all the evidence pointed in the direction that it was safe to drink and therefore it was rational to do so.

When I was a teenager, it seemed rational for me to become an atheist. The world looked chaotic and unplanned. I believed my teachers when they said the unguided processes of evolution explained the origin and development of life. The presence of so much suffering in the world seemed to argue against a deity, miracles appeared scientifically impossible, and so on. Reading atheist authors reinforced my views. It seemed logical to take a step of faith in the same direction the evidence appeared to be pointing and became an atheist.

Read the rest of these Questions from Readers at Bible Gateway!