If a person grew up in a world free of religion, would they develop belief in a god?

The "IF" questions leave a lot open. The world is not free of religion and the civilized world has never been free of it. The first Human Beings with sentience were the first to wonder about the world they lived in.

The first Humans had questions directed at other Humans.

The first Humans to answer “goddidit” became the first professional clergy.

The first Human to announce "I don't know" was the first atheist.

A world without religion has no atheists.

Thinking people would still want to know about 'first issue' questions:- Why am I here? Is there a purpose?, etc.

Two of the major religions (materiaism, buddhism) have no concept of God.

In atheist N Korea many treat the Great Leader as a god!

There are people in jungles who have never heard of "religion" or seen the outside world who believe in some sort of god or practice a religion. It's human nature to do so and the reason is that in man's instincts is the realization that there is more than our own existence in this world. It is man's search for the meaning of life. God says it's the knowledge of Him placed there in our hearts to desire to search for Him. I honestly believe that it's there and there is no such thing as a true atheist.

Wouldn't people still want to know where they May have come from? Thus make up what seems good to them then.

Look back at how many different religions and types of religions there use to be! Different cuts in stone making up what ever each t group decided on.

Religious beliefs, including belief in a god, are man-made.

I see no reason to suppose they wouldn't develop some pretty weird beliefs. Cults and micro-religions begin all the time.

Every society has religion. There is no isolated tribe that does not have some kind of religion or spirituality. If a group of people get together they are going to develop a concept of God eventually.

I believe you would somehow know that there is a supreme power. There are many things that happen in life that cannot be explained by logic or common sense. So, there must be something greater, right? It does not matter what the people would call it by name, as in biblical times, God was called Jehovah...the name doesn't matter it is still God.

Ofcourse people will want to know where they came from, how everything evolved it couldn't have just appeared with no explanation. But then again the world we are living in who knows what humans could come up with

Definitely. God's manifestation[manifestation of some sort of supreme creator] is everywhere, and the more we gain knowledge in different sciences, the more evident that becomes.

In many remote island colonies, it is common for the people to worship the sun and make sacrifices to it for good harvests, and make offerings if there is a bad Winter with strong storms. Fear motivates people on a primal level.