You have to be careful when you are quoting Job’s friends! Just because their words are recorded in scripture does not mean that what they said is good, or correct. But in Job 32:9 the younger “friend” Elihu made a good point after his older friends had finished speaking: “The abundant in years may not be wise.”
Traditional wisdom says that the older one is, the wiser they should be — and indeed in an ideal world that should be the case, but it is certainly not always so. One’s spiritual age does not always match their chronological age.
We needn’t rely upon Elihu for that; we see examples elsewhere in scripture of those who are older, but who have remained spiritual babies. Hebrews 5:12 is an example, where the author admonishes his readers: “For though by this time you ought to be teachers, you have need again for someone to teach you the elementary principles of the oracles of God, and you have come to need milk and not solid food.” These people had evidently been Christians for some time, but it did not ensure their spiritual growth.
Passage of time alone does not a better disciple make. Just because you can say, “I have been a Christian for _____ years” does mean that you are necessarily a mature Christian. A good question each of us should ask ourselves is: “What am I doing on a regular basis to ensure that I not only grow ‘older’, but wiser and more mature in my faith?”