A.He is wearing black and red. Which means he is not wealthy, but above the middle class.
B.The background tells us he is very powerful and rich. For one, his backyard is a private beach, so... he must be rich. I also got the thought by the fact he is wearing red, and holding a prayer.
C.The artist wants us to focus on him, but also what his backyard looks like to show he is rich.
D.His name is Paul. He is a highly respected priest in the upper class. In the painting, he looks like a person with a believing personality. He has a prayer in his hand so, he believes in Jesus. He doesn't have a family, and cares about the church, and doesn't like the whole change to humanism.