Interfaith dialogue: Knowing God Exists

I was reading Summa Theologica the other day and couldn’t get his imagery out of my head. So I dreamt up this dialogue: 

Kathy:  I think you can know that God exists.

Carl:  What does it mean to say that God exists anyway? Whether God “exists” necessarily depends on your definition of God.  If there is only one God, can there be more than one correct definition, and if you don’t or can’t define God, how can you know he exists?  But, if you alone decide the definition of God, then “knowing God exists” is simply affirming a personal belief in a certain definition. Right?

Kathy: St. Thomas Aquinas tells us:

To know that God exists in a general and confused way is implanted in us by nature, inasmuch as God is man’s beatitude. For man naturally desires happiness, and what is naturally desired by man must be naturally known to him.

This, however, is not to know absolutely that God exists; just as to know that someone is approaching is not the same as to know that Peter is approaching, even though it is Peter who is approaching; for many there are who imagine that man’s perfect good which is happiness, consists in riches, and others in pleasures, and others in something else.

Norman:  In terms of that example, I know God exists because I have met Him in my personal experience. I can positively recognize Him every time as the same Spirit.  I define God by the doctrines and teachings that are spoken through the Spirit.

Chris: I have felt God as well, I know God as Christ, a historical person.  I have a lot of beliefs about God but I really only trust what comes from the Bible.  If you don’t believe the Bible, you can’t really know that God exists, because you won’t know who or what God is.

Kathy: But wait, in order to identify God you must be able to identify God’s interaction with humanity,   If you can’t identify God’s church—you can’t really know assuredly God exists, because whatever you call God will either be your interpretation of your experience, or your personal interpretation of the text.   And these subjective interpretations will always result in a morass of different definitions.  The Church provides the tangible basis for the existence of God and is the only reliable basis to define and identify God.

Carl: So does the entire question come down to whether your church is also part of God’s church?

What do you all think?