[The] proposition [God is a person] is not explicitly stated in Scripture, but is an inference that Christians draw from what the Scriptures do say about God together with our concept of a person. Person is one of those words that probably cannot be defined rigorously. Nevertheless, let us loosely define the term as “a conscious purposive agent.” Conscious means that persons are things that engage in “mental” or “conscious” acts like thinking, feeling, desiring, willing, believing and knowing. Purposive means that persons are things that have certain desires, intentions or aims, and set out to achieve them. Agent means that persons are things that have the ability to act, to do or achieve things in the world.
There are perhaps other notions that are constitutive of our concept of persons. For example, a person can be harmed or benefited; a person is able to make moral judgments; a person is a member of a linguistic community; and a person is able to formulate second-order desires or wants (that is, wants about wants, like the desire to cease desiring cigarettes). Accordingly, let us say that a person is a conscious, purposive agent that possesses a significant number of the properties just mentioned. To claim that God is a person is not to claim that God is a human person. It is to say that God, like human persons, is a conscious purposive agent. In fact, Christians hold that we are persons in virtue of the fact that God is a person and God created us in the divine image.
— Stephen Davis, from In Defense of Miracles, p. 164