A strange statistic is buried in tractate Yoma. During the 410 years of the First Temple, only eighteen high priests served in succession. During the 420 years of the Second Temple, more than three hundred held the office. The difference is staggering. Roughly a ten-year average tenure in the First Temple, and barely more than a single year in the Second.
The Talmud refuses to call this a coincidence. Most of the high priests of the Second Temple era, the text says plainly, died within a year of entering the office. The high priesthood, once a long and steady calling, had become a revolving door of fresh faces and fresh graves.
The sages reach for a verse to explain it. The fear of the Lord prolongs days, but the years of the wicked shall be shortened (Proverbs 10:27). The First Temple priests, for all their flaws, still walked in a certain awe of Heaven. The Second Temple priests, by and large, had bought the office with money and politics. Flavius Josephus, writing in the first century, describes how the Hasmonean and Herodian rulers sold the high priesthood to the highest bidder. The sages saw the result on the inside, year after year.
This passage from Yoma 9a, preserved in Harris's 1901 Hebraic Literature, turns a census into a sermon. It says that the robes and the breastplate do not save a man. Only yirat shamayim, the fear of Heaven, lengthens the days of the one who wears them.