To avoid being mistaken, God’s personal name, Yahweh, does not mean love or have much to do with love. Yahweh is actually an expression of his aseity: unimpaired self-existence, I am who I am. But, his aseity will have a role in explaining God’s character and how the trinitarian depiction of him is necessary in order for love to exist in any transcendental, objective way.
I think one of the easiest ways to argue for the God of Christianity against the God of Islam, besides appealing to the historical fact of his crucifixion (The Quran claims that it was not Jesus who was crucified), is to require someone to think about what is needed to substantiate the proposition: God is love, or God is loving, or one of God’s properties is love.
Of course, I must define love in order to start using it in a philosophical discussion. Love occurs when an affection for someone is strong enough to overcome self-affection, thereby inclining the lover (one who loves) to put the well-being of the beloved (one who is loved) before his own. Let’s see whether this definition is viable by using it in an argument.
Prima facie we see that in order for love to exist multiple persons must exist, namely, the lover and the beloved. Presumably, we imagine that the relationship is reciprocal in that the beloved is also a lover and the lover, likewise, a beloved. Now, for most beings it would be the case that they are expressing love; but, could it be said that love is one of their properties? In traditional metaphysics, we could speak of properties as accidental (the thing could have existed in a different way and still legitimately be called what it is) or as substantial (once this particular property is taken away, the thing can no longer exist with the same name; it has become something fundamentally different).
A normal human being who is unified in personality could not be said to have love as a substantial property. We could imagine the human being existing without other human beings, and (for the sake of argument) without God, yet this lonely human being could still be rightly called a human being. He is rational, alive, and possesses all the other mental functions of a human. He is bereft of a beloved, however. Before we go on in this argument, someone might object by saying that a beloved is not required. The lover can express his love at something, not just someone. Consider what this would mean. The lover could have affection for a rock or a plant, but how could you ascertain the well-being for something that is not a person. Ascertaining the well-being for something is simply figuring out its purpose and acting on it in such a way that is conducive to achieve this goal. I believe that things and beings which aren’t rational cannot participate in any real way in a teleology (framework whereby purpose is ascertained and justified). Rocks can exist, metamorphosize, and be broken. Plants can grow, whither, and eject substances to continue this process into the next generation. Animals can live, die, and reproduce. All of these are not rational, therefore they are not aware of what they are doing in a teleological sense. If these things existed independently of rational beings, I don’t think their well-being could be ascertained.
Maybe you agree with what I have just argued, maybe not. It doesn’t necessarily impinge on my main argument in this post. At this point, maybe you have forgotten just what about love I’m trying to argue. Well, let me continue.
If love is not a substantial property of a human beings, but an accidental one, then there must be another source whose substantial property is love. Shall we look to The Love as a Platonist would? No. We have already said that love is a personal affair. It would make absolutely no sense to call an abstract object, namely, a Platonic form, loving. The abstract object is not a person. It has no desire, therefore it can have no affection and no reasoning for the well-being of its beloved. Shall we, if we’re theists, look to God? Which god?
An oddity emerges when we try to make loving a property of the divine. We want loving to be a substantial property of God and not an accidental one. Once we try to make God a lover, whom does he love? In the present, we could say he loves people and his creation. What would happen if we subtract people and all created things? We are told from revelatory sources and from logic that God must have existed before his creative fiat ex nihilo. Whom did he love then? Unless, we want to throw love out, we must press this slightly further. Can God be said to love himself? We already established that love without multiple persons is impossible. How could God express love if only he existed? Christianity offers the only solution. The solution is found in one of the Christian doctrines most vehemently attacked by non-Christians. Atheists say it is illogical. Muslims say it is blasphemous. Jews say it is heretical. The trinity is the solution. One in substance, plural in person, specifically three in person. Before creation, God loved himself: each person of the trinity loved the other.
But, what makes this different from the human example? Why isn’t love here also an accidental property of God? As I said earlier, love is not only affection, but a desire because of this affection to place the beloved’s well-being above the lover’s own well-being. In order to determine what is really good for someone, one needs a teleology. Now, let us suppose that in the divine example that love was not a substantial property of God, but merely an accidental one. We must then ask, “Without love how would our conception of God stand up?” If love requires knowledge of a teleology, then without love God must be ignorant of a teleology. He must have decided to create the universe for absolutely no reason. He must have no goals for himself, as well. He must sit in some kind of unimaginable state of true ignorance of what ought to be done. Maybe, you find such a god comical, well, I find him to not be God. God must be omniscient. If God were not omniscient, then there would be reality that exists apart from him. In order for this additional reality to be, another God would be required for causative purposes. God cannot exist in a state of ignorance of purpose. If we cannot conceive of God without love, then love must be one of his substantial properties.
Not only is love here a substantial property, love is found in God to be in a totally uncorrupted form. Humans do not have full understanding of the real teleology of existence, therefore any love we express will at times be inadequate, because we direct our beloved toward a well-being that is not really good. Since God possesses pure love, we can say that he possesses a necessary version of it (reality could not have been furnished in such a way without the love God has because God is eternal and immutable and love is a substantial property of his). If God possesses a necessary version of love, then all other counterfeits of it could not legitimately be called love, therefore the people expressing this form of “love” could be said to be unloving–evil. Here we find the connection between morality and love. They are part of the same account of God’s character.
If we want to say love is anything more than qualiae (internal, mental experience due to the excretion of certain neurotransmitters), then we must appeal to God. He must be multi-personal and not unitarian like the God of Islam or the mistaken interpretation of God in Judaism or the mysterious god of creation in many polytheistic religions.