In 1 Peter 2:18 it says:
"Servants, be submissive to your masters with all respect, not only to those who are good and gentle, but also to those who are unreasonable."
Respect is not always simply 'being nice', sometimes (many times, actually) in order to show respect, you must do what you are told to do, even if it is 'unreasonable'. I'll give an example. Let's say Alice is walking on the beach. She is thinking of how soft and warm the sand is when it squishes between her toes. After a while, Alice's sister comes up to her and says, "Alice, you need to put shoes on." This may seem ridiculous. After all, the sand is so soft and warm and clear. Alice asks a simple question, "Why?" Her sister replies, "Because mom said so." Alice should need no other command. Even though wearing shoes may seem ridiculous to her, her mother may have good reasons why she should. Though the command may appear unreasonable, it is a command and it should be followed.
So it is with nearly all authority. Not only with our parents or our political leaders, but with all those whose experiences have taught them what is better and what is worse. I'm not saying that everyone who is older is right, but when someone gives advice it should be carefully considered, and when someone gives a command, if it isn't contrary to the laws that God has placed on us, it should be followed.
In Proverbs 16:31 it says:
"A gray head is a crown of glory; it is found in the way of righteousness."
As I said above, those who have gone before us have gained a knowledge that nothing but experience can help them gain*. They've gone through much more than we have. They've had more sorrows and more joys. They can give better advice, because they've seen how things have turned out before. Their life and the information they've obtained in their life deserves recognition and respect.
Other scriptures to read and consider would be Exodus 20:12, Leviticus 19:32, Proverbs 4:1, 23:22, Ephesians 6:1, Titus 3:1, and 1 Timothy 5:1.
To be continued...
*Please note that I am speaking in generalities here. I'm not referring to all the "gray haired" people in the world. I'm speaking mainly of those more elderly people who have lived a full life and who have a love for God. Their advice is indispensible.