Towering intellects like:
Augustine
Aquinas
Descartes
Newton
Pascal
Kierkegaard
et. al.
all believed in God, therefore so should we lesser intellects.
Besides their belief in the Christian God, what else do all these men have in common?
They've all been dead for at least 150 years and most of them for more than two centuries.
Do you think that it is only coincidental that most of the great minds that live today are agnostic or atheist?
Augustine is one of the most important thinkers in Western history. So are Aquinas, Descartes, Newton, Pascal, and Kierkegaard. But they all lived during a time when Christianity was a subject not to be reasoned about. They lived during a time when Christianity was assumed.
The quoted argument is like an argument that goes, "Because Plato, Aristotle, Ptolemy, Galen, Augustine, Aquinas, and virtually all other major thinkers of the first millenium and earlier believed that the sun orbits the earth, and not vice versa, we have good reason to believe that the sun actually orbits the earth."
But we don't have 'good' reason today to believe that the sun orbits the earth and we have every reason to believe that it doesn't. Today we know that those brilliant men were just plain mistaken.
Prior to the sixteenth century this kind of argument from authority was by far the most common form of argument used in disputation. Back then, the words of Aristotle and other ancient authorities were taken to be gospel. Arguments began with these authorities' pronouncements as unshakable premises. It wasn't until Bacon, Descartes, and others lived and wrote that the words of ancient authorities could even be legitimately questioned; and it wasn't until their words were legitimately questioned that knowledge about the world exploded.
A belief in a proposition that was perfectly reasonable five centuries ago, may not be reasonable today. That a well-educated person living 500 years ago might believe that the sun orbits the earth is entirely understandable. That a person with a decent education from any Western university today might believe the same is not.
Knowledge is not fixed. It is accumulative. We simply know more about the world today than we knew about it yesterday. We'll know still more about it tomorrow. I know more about how gravity works than Aristotle knew. So do you. Now granted, all of our brains combined wouldn't equal a decent sized neuron in Aristotle's head but that's beside the point. Fortunately for us, we don't have to depend on our own original mental discoveries about the world to know about the world. We get to stand on the shoulders of intellectual giants and look and know.
All that's required of us is that we open our eyes and look without bias.