This question was asked on the Quora forum. This was my reply.
I’m always amazed at how easily people can say “believe in God” as if it means something objective, that is, the same thing for everyone who says it. Saying “do you believe in Sol or believe in Earth?” (the names of our star and planet) requires a category distinction from the concept of “believe in God”. It is thus impossible to answer *your* question, because you have not defined the terms “believe” and “God.” So any attempt to answer the question requires the responders to provide their own definitions of believe and God, meaning they will be answering their question, not yours. Here, your invitation includes the BYOB that means “bring your own beliefs.”
First let’s address “believe.” There are several terms with a shared meaning element: belief, trust, confidence, and faith are in the overlapping rhetorical region. I can say, “I believe that when I sit down on it, the chair will support me.” Is that the “believe” you mean? Or do you mean “I believe in unicorns, because people have drawn pictures of them.”? Same word, with completely different bases for its use. When Carl G. Jung was asked if he believed in God, he said, “No, I don’t believe, I know.”
And this brings up the second issue to address, what is meant by the word “God”? What is the concept, the meaning, the image, that is within the word and it’s use? This is the holy grail of the question. What is your God concept? Two people can both say, “I believe in God” but their concepts of God can be completely different when saying the identical word. Carl Jung was talking about the psychological experience of God, so he could say he “knows,” and “belief” was not part of the question, any more that whether the quenching aspect of water is a matter of belief. In other words, only people who have no experience of God, speak of believing in God, like believing in Unicorns.
If the question is “Can you still be a Buddhist if you believe in the God of another religion?” then the answer is “it depends.” What is a Buddhist? The word means a follower of the Buddha Dharma (Pali: Dhamma). The traditional declaration of being a follower of the Buddha Dharma is “I go to the Buddha for refuge; I go to the Dharma for refuge; I go to the Sangha for refuge.” All three words, Buddha (the Awakened One), Dharma (the teaching, method, and pattern of life articulated by the Awakened One), and Sangha (Community of followers of the Buddha Dharma) have multidimensional meanings, but primarily each word has three levels of meaning: the conventionally concrete, the imaginatively metaphorical, and the absolutely ultimate.
If you are in fact and in deed a follower of the Buddha Dharma, then you have thrown in with a different view of the universe than the one that has a Father-Creator-God as the Supreme Person who is objectively separate from you. In fact, that is not even “the Father” of Jesus’ teaching, because Paul’s Christianity used an entirely different conception of God than Jesus had. We Buddhists don’t deny the God realm or the God beings who populate it, or what Carl Jung called the Archetypal Realm populated by the Archetypes, but we have a different view of it because, like Jung, we see that there is an inherently subjective aspect to the God realm that cannot be removed. In terms of the “personage” of God, Buddhist see the “person,” “personality,” or “self” of both humans and gods as an illusion, a phantom, or a dream, i.e. a psychological and imaginal construct. In this context, one of the titles of the Buddha is “the Teacher of Gods and Humans.”
As a Buddhist, you can believe in or imagine the God whom the Buddha teaches as his student. But there is no room for belief in a God that creates the Buddha. This is because if you are a follower of the Buddha Dharma you have at least a basic understanding that nothing is “created” in such a supernatural sense and all things appear by the causes and conditions of deeds and events from moment to moment through causes bearing fruits, and fruits becoming seeds for successive causes (to use the traditional agrarian symbolism).
Alternatively, you can re-frame the whole concept of God into Buddhist terms.
Buddhism has many terms for the ultimate reality: Tathata (Thusness),
Dharmakaya, Sunyata (Emptiness), True Suchness, One Mind, etc. The LankavataraSutra has a list of names that include the names of Hindu Gods as well as names
like “the Sun” and “the Moon” as names of the Buddha Tathagata. "The
same, Mahamati, can be said of myself, for I come
within the range of hearing of ignorant people, in this world of patience,
under many names, amounting to a hundred thousand times three asamkhyeyas, and they address me by these names not knowing
that they are all other names of the Tathagata. " (pp. 165-166) That is, when
surveying the highest representation of every other religion, the Buddhist sees
that name as a synonym of the Buddha Tathagata of Buddhism. In this context, believing in God is believing in the Buddha Tathagata by another name.
The first Zen Buddhist to come to America 120 years ago was Soyen Shaku who was accompanied by D.T. Suzuki as his young translator. After his visit he wrote a book titled Sermons of a Buddhist Abbot [Zen For Americans] published in 1906. The Zen Teacher Shaku addressed this question as “The God-Conception of Buddhism.” He said that Buddhism was not theism (God as objective transcendent person) or atheism (no God), or pantheism (God identified with the objective universe), but the closest Western term for Buddhism is panentheism (absolute and transcendent, simultaneously all and one). He comments,
“[H]ere Buddhism is speaking of our inmost religious experience, which deals directly with facts and not with their more or less distorted intellectual reflections. It is, therefore, really idle to say that Buddhism is pantheistic or atheistic or nihilistic. Buddhism is not a philosophical system, though it is the most rational and intellectual religion in the world. What it proposes is to make clear facts of the deepest spiritual life and to formulate a doctrine which leads its followers to the path of inward experience.
“Thus, according to the proclamation of an enlightened mind, God or the principle of sameness is not transcendent, but immanent in the universe, and we sentient beings are manifesting the divine glory just as much as the lilies of the field. A God who, keeping aloof from his creations, sends down his words of command through specially favored personages, is rejected by Buddhists as against the constitution of human reason.”
One way it has been said is that Buddhists have faith that every person can awaken and become a Buddha and that the essential nature of people and Buddha are one and the same, and therefore a belief in a God as a heavenly entity or personality is essentially irrelevant to walking the path of the Buddha Dharma for one’s own realization of liberation and Buddha's awakened knowing and seeing.
