> You mean brought up to be Muslims. No one is born with religious beliefs or faith.

In Islam, it is common belief that all people are born Muslim, then their parents may choose to lead them away into another religion.

That's why for people who convert to Islam later in life (muallaf) it is sometimes said that they reverted.

> Every child is born with the fitrah, but his parents make him a Jew, Christian or a Zoroastrian. ~Al-Bukhari