Question:
What is the difference between a young man and an old man?

Answer:
1 John 2:12-14:

Young men are fighting, but when learning to use the sword, they don’t always use it rightly for they are practicing.
The babes in Christ know their sins are forgiven.
The young men overcome the wicked one through the Word, so get to know the Word.
The old men or fathers are taken up with Christ, He who is “from the beginning.” So young men, when we mess up, all is not lost. Learn to know Christ better in the Word, and learn from the experience. Be Peters not Thomases.