What is the virtue of a Muslim by birth over one who is guided to Islam?

There is no legal text that prefers a Muslim born to Muslim parents over a Muslim born to non-Muslim parents. Superiority in Islam is based solely on piety and good deeds, as Allah the Almighty said: (Indeed, the most noble of you in the sight of Allah is the most righteous of you). Despite the influence of environment and upbringing, every child is born with an innate disposition toward Islam (fitra). Therefore, scholars have ruled that a child born to Muslim parents, or one of them, or in a Muslim environment, is considered Muslim, and they have mandated offering prayers for them.