One thing that this friend knew that many others do not know is that there is a difference between the Judeo Christian view of God, and Buddhism. If there was no difference there would be no need of leaving one for the other. So let's get down to the real issue on this subject.
What is the difference between the view of God in Christianity and Buddhism? Let's throw in another religion, Hinduism. What is the difference between Christianity and Hinduism? What do these eastern religious views of their deities have in common if anything? Do the eastern religious views line up with the Christian view of God? Let's look at a quick answer to these questions.
In order to know the real from the counterfeit, it is important to get familiar with the real before detecting the fake. To do this, let's deal first with the Christian view of God. The God of Christianity is the personal, timeless, immaterial, First Cause of the existence and design of the universe, revealed simultaneously in God the Father, God the Son (Jesus Christ) and the Holy Spirit. Biblical Christianity is monotheistic, meaning one God; and God is the transcendent Creator of heavens and the earth, but He is separate from His creation.
Looking at the eastern religions, Hinduism and Buddhism, allow me just to give you a quick snippet on how different they really are, not just from from the Judeo Christian view of God. Most Hindus are pantheistic and for the most part polytheistic.
Pantheism is the belief that all is god, and god is all. In Hinduism there is a pantheon of over 300 million deities (polytheism - many gods). At the same time there is a diversity within Hinduism which allows for other concepts, including monotheism, henotheism (one god among many), and monism (only one eternal reality exists and everything comes from it). Hinduism's most popular gods are Shiva, Brahma, and Vishnu, who have come to earth in various incarnations avatars) to aid human beings.
For Buddhism, it is different. While Hinduism believes in many gods, making up "the One," Buddhism is a response to Hinduism in that it is a belief system of those who follow "the Buddha." The Buddha is "the Enlightened One, given to its founder. There is no personal transcendent Being, known as "God" with Buddhism, which in essence makes it "atheistic." There is no personal relationship with the Buddha, or any past saviors who have forgone nirvana to help others achieve it.
There you really have it, in "a nutshell." The view of God from the Christian worldview is different from the views of the "divine" in both Hinduism and Buddhism. So when a "nutty" humanities professor tells you that all gods are the same and they are really just called different names, remember this posting. I hope you have been encouraged and challenged to stand firm on the view that not all religions are the same, at least in their views of God.