This proverb means that the experiences of different people influence the credibility of their words in the eyes of others. A creditor may not be believed by a hypocrite, an onlooker will not be taken seriously by the one who works or makes things, and a lazy person will not be believed by someone who is diligent. In other words, people tend to doubt those whose experiences or viewpoints do not align with their own efforts or interests. The equivalent English proverb would be: ‘Actions speak louder than words.’