I get asked this question often when it comes to people of different religions. And the answer is, to put it bluntly, no.
Indeed I tell the person asking. You don’t believe in God. No one believes in God.
Because God by definition is that which is transcendent, limitless and can thus never be the object of belief by a finite human mind. None of us can believe in God because the word designates that which is beyond our capacity to grasp with our minds.
What we can believe are certain limited facts about God, attributes of God that are within the capacity of our mind to grasp.
So, for example, Paul tells us (Romans 1:19-20) that all humans can see that God is the creator of everything we know. “For what can be known about God is plain to them, because God has shown it to them. Ever since the creation of the world his eternal power and divine nature, invisible though they are, have been understood and seen through the things he has made.” The key phrases here are “what can be known about God” and “through the things he has made.”
Now I know that some Christians will say: what about Jesus? Isn’t Jesus fully God and therefore a complete revelation of God? And the answer for us comes from the forthright truth-speaker, John: “But there are also many other things that Jesus did; if every one of them were written down, I suppose that the world itself could not contain the books that would be written.” (21:25) Exactly.
This is why the Christian Creeds never begin with “I believe in God.” They begin “I believe in God the Father Almighty, Maker of Heaven and Earth.” The first thing that Christians can say about God is based on their experience of the revelation that Jesus is the Son of God, which is that God is the “Father.”
The second thing they can say is based on the experience of the Son of God as the Christ, the Lord who shows his power from the Father over both creatures (not least angels and demons) as well as the created order (wind and waves.) God the Father is Almighty.
As for the rest of the creeds, they affirm either what was witnessed historically or what their writers believed was revealed in scripture; the compliment and extension of the person of Jesus Christ.
So, to be clear. We Christians don’t believe in God. We believe a rather limited number of very important things about God that God reveals through God’s incarnation in Jesus.
The same limitation on belief is true, I would add, for Jews and Muslims. Both groups recognize the finitude of their data about God. Indeed both groups explicitly (following their respective scriptures) recognize that God has been active in the lives of other peoples whom they have never known and that the revelation each possesses may be final but it is not complete.
As for Hindus and Buddhists, well their philosophical reasoning has always pointed out the limited human capacity to know that which is transcendent. So to the extent that they would even use the word “God” (Hindus more than Buddhists) they would designate a mystery out of which the created order and the human self emerges; the “creator of heaven and earth.” Taoist would say the same, explicitly identifying the Tao with creation while affirming that “The Tao you name (and thus limit so that it can inhabit your mind) is not the Tao.”
I realize that this doesn’t solve all the problems of how people of different religions should relate to one another, but I hope will keep us from asking at least one bad question, and thus begin to focus on some better questions.
One of which is how we can fruitfully, through dialogue, share our limited knowledge of God with one another and thus possibly expand it.