The Bible and Patriarchs
If the Bible is inerrant, explain the old age of the Patriarchs.
Pope Leo XIII wrote that Catholics must: 'carefully observe the rule so wisely laid down by St Augustine â€" not to depart from the literal and obvious sense [of Scripture], except only where reason makes it untenable or necessity requires.' So, we should interpret Scripture giving pride of place to the obvious meaning without being slavishly literal (see DS 3373 from the PBC an organ of the Magisterium up to 1971; Sheehan p 263). For example, it would be absurd to believe that Jesus was actually calling Himself a 'sheep gate' in Jn 10:7. As to the longevity of the Patriarchs (eg Methuselah lived 969 years in Gen 5:25): for well over 1500 years of the Church's history no serious challenge was offered to the consensus that the patriarchs actually lived to those old ages. It is a teaching of the Church that the first humans were created with immortality, so God's original plan included a human body, and an environment in which it lived, that was conducive to immortality. After Original Sin, and before the Flood (that drastically altered the living conditions on the planet), the ages of the patriarchs is seen to steadily reduce until the Flood, then it plummets until around the time of Moses where we see ages just as our own today. The idea of extremely old-aged people seems absurd to us because it is not in our experience to know extremely old-aged people, but our own experience does not make the longevity of the patriarchs impossible. A pure gene pool amongst our first ancestors, an altered air-pressure, a difference in the Earth's magnetic field, minimal pollution (as was possible pre-Flood), may all have played a part in the longevity of the Patriarchs (creationresearch.net).
* Please note that this text should be read in the context of the whole work and in recognition of the appropriate paragraphs of the Catechism of the Catholic Church highlighted in the index.