And although it is completely true that we should believe in the existence of God because it is taught in the holy scriptures, and by the same token that we should believe the holy scriptures because we have them from God since, faith being a gift of God, he who gives us the grace to believe the rest of religion can also give us the grace to believe he exists there is no point in asserting this to unbelievers, because they would call it arguing in a circle.