Does the utterance of the words ‘God exists’ amount to a meaningful utterance? Does this utterance express a statement?  Two considerations support the claim that this is a meaningful utterance:
1. ‘God exists’ is a grammatical sentence.
2. The word ‘exists’ has an established meaning.

The main question to consider is whether the word ‘God’ has a meaning.

Many utterances of the form ‘X exists’ are obviously meaningful utterances that express a statement:

• Chickens exist.
• The Earth exists.
• Oxygen exists.

Plenty of false and implausible statements are of this form:

• Unicorns exist.
• Ghosts exist.
• ESP exists.

But such false and implausible assertions, are still utterances of meaningful sentences.  In fact, we can know such assertions to be false or implausible only because we understand what they mean.

But what about the word ‘God’? Does this word have an established meaning? 

No doubt the word ‘God’ is a bit unclear apart from some context.  There are a diversity of views and beliefs about ‘God’ and about religion among human beings.  But if the assertion ‘God exists’ is placed in the context of traditional Jewish or Christian religious belief and theology, then that narrows the possible meanings considerably.

There is a core concept behind the term ‘God’ that provides an initial clarification of this term:

Definition 1:  Something is God if and only if it is the only perfect person.

This definition is somewhat unclear, but it seems to me to be clear enough to show that the utterance of the words ‘God exists’ in the context of traditional Jewish or Christian belief/theology is a meaningful utterance that expresses a statement.

This concept of God is somewhat unclear and problematic because the word ‘perfect’ is a normative term, and given the diversity of norms and values among human beings, it is less than obvious what would constitute a perfect person.  However, the unclarity and ambiguity here is not so extreme that we have no idea what the phrase ‘perfect person’ means.

In any case, in the context of traditional Jewish and Christian belief, we have a pretty good idea of some of the implications of the idea of a ‘perfect person’ and can cash out this concept in somewhat less problematic terms:

Definition 2: Something is God if and only if it is the only person who has unlimited knowledge, unlimited power, and unlimited freedom.

This definition contains the divine attributes that Swinburne sees as the core divine attributes.  Other divine attributes are inferred from these core attributes. 

These core divine attributes are not perfectly clear; each of these attributes is itself in need of careful definition, if one is to think clearly about the existence or nature of God.  But  one does not need to acheive the crystal clear conception of a philosopher of religion in order to understand the meaning of ‘God exists’.  Clarification is an iterative process, and a learning process that requires time and effort.  One must start somewhere, and it seems to me that Definition 2 provides a good starting point for thinking about ‘God’ and the assertion ‘God exists’.

If one does not buy Swinburne’s attempt to derive the divine attribute of perfect goodness from the three divine attributes in Definition 2, then we can just modify the definition to specify this other attribute:

Definition 3: Something is God if and only if it is the only person who has unlimited knowledge, unlimited power, unlimited freedom, and is perfectly good.

There is enough meaning and clarity here to start engaging in intellectual enquiry into the question ‘Does God exist?’, and that implies that the words ‘God exists’ make a meaningful sentence that expresses a claim or statement, an idea that is true or false, accurate or inaccurate, probable or improbable, supported by available evidence or not supported by available evidence.

The divine attribute of ‘perfect goodness’ brings back the issue of normative concepts (i.e. moral goodness).  Human beings hold a diversity of beliefs and values concerning morality and ethics, so the attribute of  ‘perfect goodness’ brings some unclarity and ambiguity into the concept of ‘God’.  One can choose, like Dawkins does, to simply cut out the normative aspect of the concept, and define ‘God’ in purely descriptive terms (e.g. as the creator or cause of the universe), but this is a significant departure from the concept of God in traditional Jewish and Christian religious belief and theology.  So, I prefer to maintain the normative aspect of the concept, and to remain cautious and aware of the problematic and ambiguous nature of general normative concepts like ‘moral goodness’.

Perhaps it is best to think about the assertion that ‘God exists’ as a mixed claim that makes both a descriptive claim, and a normative one:

Definition 4:  Something is God if and only if
(a) it is the only person who has who has unlimited knowledge, unlimited power, and unlimited freedom, AND
(b) that person is also perfectly good.

This definition might not be satisfactory as a technical definition for professional philosophers, but it is sufficient to show that the utterance of the words ‘God exists’ constitute a meaningful sentence that expresses a statement.