The purpose of the first of five phases of Swinburne’s case for God is to show that the statement ‘God exists’ makes a coherent factual (logically contingent) statement.  He thinks he has accomplished this in his book The Coherence of Theism (revised edition, hereafter: COT) for a somewhat pared-down concept of God, that he calls a ‘contingent God’.  A ‘contingent God’ is one that has most of the usual divine attributes, except for necessary being.

The meat of COT is in Part II (Chapters 7-12), where Swinburne argues that ‘God exists’ makes a coherent factual statement, when we understand ‘God’ to be a ‘contingent God’.  Swinburne, like a good analytic philosopher, begins by analyzing the assertion ‘God exists’, breaking it down into bite-sized pieces, or to make the metaphor more accurate, into meal-sized pieces.  The assertion ‘God exists’ means:

…there exists eternally an omnipresent spirit, perfectly free, the creator of the universe, omnipotent, omniscient, perfectly good, and a source of moral obligation… 
(COT, p.241)

Swinburne breaks the concept of God down into various divine attributes, and then slowly re-assembles the concept, piece by piece.  He has two kinds of tasks to perform in doing this re-assembly.  First, he must show that each individual piece is coherent.  In other words, he must show that each of the following assertions makes a coherent statement:

(1) A spirit exists.
(2) An omnipresent person exists.
(3) A perfectly free person exists.
(4) A person who is the creator of the universe exists.
(5) An omnipotent person exists.
(6) An omniscient person exists.
(7) A perfectly good person exists.
(8) A person who is a source of moral obligation (for human beings) exists.
(9) A person who is eternal exists.

Showing that each of these assertions makes a coherent statement is not, however, sufficient to show that ‘God exists’ makes a coherent statement.  Even if each of these assertions is meaningful and coherent, the combination of two or more of these divine attributes in a single person might involve a logical contradiction, and if such a logical contradiction exists between two or more of these attributes, then the assertion ‘God exists’ would involve a self-contradiction.

For example, I mentioned in Part 1, that Swinburne significantly constricts the concept  of ‘omniscience’ in order to avoid a logical contradiction between ‘omniscience’ on the one hand and ‘perfect freedom’ on the other.  If God is perfectly free, then God cannot predict his own future choices, because perfectly free choices cannot be determined by what has happened in the past.  Thus, God does not have full and complete knowledge of the future, because God does not know in advance what choices he is going to make in the future. 

So, Swinburne slowly re-assembles the concept of God, adding divine attributes back into the mix, one (or two) at a time, showing at each step that the new combination of attributes is coherent.  By the end of Chapter 8, for example, Swinburne thinks he has shown that the following assertion makes a coherent statement:

…there exists an omnipresent spirit who has free will and is the creator of the universe…
(COT, p.129)

In other words, the first four of the above assertions about individual divine attributes are coherent, and the assertion of the existence of a person having all four of those divine attributes also makes a coherent statement.

By the end of Chapter 12, Swinburne thinks he has shown that the assertion that there is a person who has all nine of the above divine attributes makes a coherent statement, and thus that ‘God exists’ makes a coherent statement, if we understand ‘God’ in the pared-down sense of a ‘contingent God’.

Note: the attribute ‘eternal’ works a little differently than the other attributes.  It qualifies most of the other attributes.  For example, God is ‘eternally omnipotent’ and ‘eternally omniscient’ and ‘eternally perfectly good’.  God is not just omnipotent some days, and less than omnipotent on other days; God has always been omnipotent and always will be omnipotent.  Any being who is only omnipotent for a few days or a few years or a few centuries does not count as ‘God’ according to Swinburne’s analysis of this concept.