"Act well your part; there all honor lies." by Alexander Pope

This quot is meaning to say that by acting well, your honor will show there. Also that you are a loyal person by doing your part well. As in 'act well your part' means that you have to do what you have to do in a complete honest and right way. And that what it means by 'there all honor lies.' For example, being loyal to people as in not spreading rumors about them is a way of doing well. Saying and doing bad things to other people and lying about it is not being loyal nor honest. People need to make right decisions in what they do. The picture represents someone talking about someone else. Obviously that is not being loyal and honest to the person.