In one of his latest Reasonable Faith podcasts, "A Rabbi Looks at the Kalam Argument," William Lane Craig explains that he accepts the Aristotelian-Thomistic proof for the existence of a first cause in the order of efficient or sustaining causes. At the end of the podcast, he enunciates an argument one of his students came up with for the personhood of the first cause, which has necessary existence.
1. The necessary being N is either personal or impersonal. (Definition)
2. If N is impersonal, then it cannot cause any contingent effects. (Premise)
3. N does cause contingent effects. (Premise)
4. Therefore, N must be personal. (From 1 - 3)
Craig explains that N cannot cause contingent effects if impersonal, in confirmation of (2), because an impersonal cause would be mechanical. Such a cause could therefore only produce necessary effects, in violation of (3). It's interesting to note that this argument very much resembles Craig's argument for a personal creator in his defense of the kalam cosmological argument. The advantage here is that the connection between N and personhood is not dependent upon the universe's having had a beginning, unlike the kalam argument.