Humans seem to have a natural abhorrence of an infinite regression of causes, and this distaste is at the root of the most famous and the most
effective demonstrations of the existence of God by Aristotle and Thomas Aquinas. But these thinkers lived before the infinite series was a mathematical commonplace.
If the differential and integral calculus or transfinite arithmetic had been invented in Greece in the 5th century B.C., we would have seen less of the pretension that theological doctrine can be convincingly demonstrated by rational argument to those who reject alleged divine revelation, as Aquinas attempted in the Summa Contra Gentiles.