It's no secret that respect for one's elders is a strongly taught concept in the Scriptures. And indeed, for good reason. Sadly, like all of the Scriptures, this can be abused. I've seen it many times myself: An older person, particularly men older than 60, often brag about their age, and how they think the Bible says this makes them above reproach.
But though Elihu was young when he spoke the words of Job 32:7-9, he is far older than anyone breathing. His message? Great men are not always wise, nor do the aged always understand justice.
While the Bible certainly preaches respect for those older than us, it is not intended as a trump card to be played in defence of bad theology, and especially not in defence of sin. You may well be 70 years old, that does not give you the right to demand a 20 year old cease to preach Creationism. Perhaps you are 80, since when does that give you a free pass on telling a 20 year old her taste in music is demonic because she praises God with a bass instead of a piano? These are just two examples I've seen in my personal life. Wrinkled skin does not excuse wrinkled theology.
In 1 Timothy 4:12, Paul tells Timothy "Let no one despise your youth, but be an example to the believers in word, in conduct, in love, in spirit, in faith, in purity." As often as some older Christians like to throw their age around as if it were the Lord's signet ring, the Lord looks upon the old and the young with the same eyes. If anything, arrogance in age may increase the judgement thereof, for we know the Lord expects much from those to whom He gives much, and those who know little are punished less for the same crime than those who know much (Luke 12:48).
At any rate, age means little to nothing. The young would be wise to listen to the old, but sometimes the old have a lot to learn from the young. As with Job and his three friends, sometimes the old can benefit from listening to the young.
Furthermore, let us consider Paul's words in 1 Corinthians 1:27-29: "But God has chosen the foolish things of the world to put to shame the wise, and God has chosen the weak things of the world to put to shame the things which are mighty; and the base things of the world and the things which are despised God has chosen, and the things which are not, to bring to nothing the things that are, that no flesh should glory in His presence."
God, being God, is quite intent on receiving the glory that is due to Him. You may be wise, but God is wiser. You may be strong, but God is stronger. You may be beautiful, but God is far more spectacular. You may be old, but my friends, the Lord is eternal. That being the case, when men begin to brag, when flesh seeks to glory, God is not afraid to knock us down a peg or two. He can use a child to make a centurion look foolish. A pastor can be flattened by a new convert. A scientist can be knocked down by a high school dropout. A criminal can school a lawyer, a jester can embarrass a king, the only one above reproach is the very God who makes all of these anomalies a glorious possibility.
And so, to the young, I say this: Let no one despise your youth. Stick with the Lord, study His word, and He may one day use you to humble the proud. By all means, listen to those who are old, but do not allow them to use their age as a weapon. To the old, I say this: Stick with the Lord, study His word, and be humble, because you are called to be wise, and examples to the young. Seek to share wisdom with the young, but do not assume your every opinion trumps their every word. Whoever you are, make God your focus, and boast only in Him. Anything else is pride as rickety as a plywood step ladder. He's not afraid to knock you down.