An Old Crab said to her son, “Why do you walk sideways like that, my son? You ought to walk straight.”
The Young Crab replied, “Show me how, dear mother, and I’ll follow your example.”
The Old Crab tried, but tried in vain, and then saw how foolish she had been to find fault with her child.
EXAMPLE IS BETTER THAN PRECEPT. (Reference: Aesop’s Fables)

Jesus said, look not at the speck in your brother’s eye when you have a log in yours (Matthew 7:3). We are to be an example; an example in word, in conversation (conduct), in charity (love), in spirit, in faith, and in purity (1 Timothy 4:12).

Matthew 7:3-5 (ESV)
3 Why do you see the speck that is in your brother’s eye, but do not notice the log that is in your own eye? 
4 Or how can you say to your brother, ‘Let me take the speck out of your eye,’ when there is the log in your own eye? 
5 You hypocrite, first take the log out of your own eye, and then you will see clearly to take the speck out of your brother’s eye.

1 Timothy 4:12 (KJV)
12 Let no man despise thy youth; but be thou an example of the believers, in word, in conversation, in charity, in spirit, in faith, in purity.