A person’s religion is most often a question of where he or she was born and grew up. Everyone is born into a cultural context, which includes religious beliefs, and this culture is “imprinted” on the minds and hearts of everyone within it.
People born and raised in the U.S. will likely be oriented toward the Christian religion – in all its different manifestations. For example, I was baptized a Catholic in a Catholic church by a priest when I was six months old. My education and cultural indoctrination carried the constant subtext of Christianity (often correlated with Patriotism and Country).
If I had been born in Tehran, I’d be Muslim; if I’d been born in China, I might be Buddhist.
In this sense, most people don’t choose their religion. Our religious beliefs do not come to us after careful study of all alternative explanations for the Universe. Rather, it’s a matter of indoctrination and conditioning. We’re constantly exposed to a religion and we absorb it.
How can we possibly say that any particular religion, or lack of one, is “right” or “wrong?”