The view of The Church over many centuries has been that the individual persons of the Trinity do not each have their own will, rather God has one will. This will is a property of his nature. This also leads to the conclusion that Jesus, having two natures, must have two wills, one human and one divine.
Why is this so important? Well, to answer that question, there are three specific things we need to consider.
- Essential and accidental
- The oneness of God
- What will -and specifically what the will of God is.
Essential and Accidental
In philosophy, the word accident does not refer to stubbing your toe or crashing the car. Rather, Aristotle made a distinction between things that are essential and things that are accidental. If an attribute is essential to someone, then it belongs to their essence. It is a permanent and necessary characteristic of their nature. If something is accidental, then it is a property that may or may not belong to their character without affecting their true identity.
This is important when we are talking about God. You see, when we talk about him, we insist that God is simple. This means that he is not a complex being with lots of different parts. Rather, God is Spirit. It means that God can’t really have characteristics that are accidental to him. God can’t stop being loving, holy, just or eternal without ceasing to be God.
So, we are saying that God’s will is an attribute of who he is and so is essential to him.
The oneness of God
Remember that we cannot deny the unity, equality and distinction of the persons in the Godhead.If God has three wills belonging to the different persons then we risk moving beyond distinction to creating partition and division in God. This would lead to there being three different seats of will and authority within God with the potential for rivalry.
Will and God’s Will
We use the word “will” to describe someone’s settled view and intention on a matter. It is about their expressed purpose and what they desire to see happen. When someone dies, their will is read out. This is an expression of their intentions and desires for what should happen to their estate after they die.
So, God’s will is about his decrees. It is about his purpose to see a people bought back to himself through the redeeming act of Christ. Once again, it is important that we recognise that God has a will and that this is a will, singular because it results from his divine nature. Hodge explains it this way:
“If God is a spirit He must possess all the essential attributes of a spirit. Those attributes, according to the classification adopted by the older philosophers and theologians, fall under the heads of intelligence and will. To the former, are referred knowledge and wisdom; to the latter, the power of self-determination, efficiency (in the case of God, omnipotence), and all moral attributes. In this wide sense of the word, the will of God includes: (1.) The will in the narrow sense of the word. (2.) His power. (3.) His love and all his moral perfections. In our day, generally but not always, the word “will” is limited to the faculty of self-determination.”
So, for Hodge, God’s will is about the faculties that he has which enable him to think, know, love and decree. However, whilst we talk about one divine will, we also need to note that theologians have begun to make distinctions concerning that will. So, for example, Hodge goes on to say:
“It is said, that God wills Himself necessarily, and all things out of Himself freely. Although the word seems to be taken in different senses in the same sentence, God’s willing Himself means that He takes complacency in his own infinite excellence; his willing things out of Himself, means his purpose that they should exist.”
So here, Hodge starts to distinguish God’s immanent will, concerned with the inner life of the Trinity from his outer (economic will) which is concerned with what he decrees towards creation.  Bavinck observes that:
[God] “did not just begin to work at the time of creation for his works are from eternal and everlasting to everlasting. God’s personal attributes … are he immanent and eternal works of God. The Father eternally gives to the Son, and with him to the Spirit to have life in himself (John 5:26). And the community of being that exists among the three persons is a life of absolute activity. The Father knows and loves the Son eternally -from the foundation of the world (Matt11:27; John 17:24) -and the Spirit searches the deep things of God (1 Cor 2:10). They bear no relation to anything that exists or will exist outside of God, but occur within the divine being and concern the relations among the three persons.”
Once again, we see that the outer will of God is distinguished from the inner will. The inner will does concern the relationship of the persons and is seen in terms of the Father’s love for the Son and the Spirit’s investigation of deep things.
In later posts we are going to look in more detail at the EFS argument and how its proponents handle the question of relationships within the Trinity
 Hodge, Charles. Systematic Theology: The Complete Three Volumes (Kindle Locations 7618-7623). GLH Publishing. Kindle Edition.
 Hodge, Charles. Systematic Theology: The Complete Three Volumes (Kindle Locations 7628-7630).
 Bavinck, Doctrine of God, 342.
 Bavinck, Doctrine of God, 342.