Paul: "I have learned, in whatsoever state I am, therewith to be content. I know both how to be abased and how to abound: everywhere and in all things I am instructed both to be full and to be hungry, both to abound and suffer need."
Thomas a'Kempis: "You must be ready alike for suffering or rejoicing. You must be poor and needy as willingly as full and rich."
Paul speaks of being content while Kempis speaks of something a tick more active, in affecting a good humor towards whatever circumstances. So we establish that being content is passive, but no less good than embracing the experience that is before you.
Herein, we had Peace vs Joy debates at a local church, with the one side(me) saying that I had prayed for peace from my Lord, and he was gracious in bestowing it upon me. Meanwhile, the other side claimed joy from God. On the surface, the two states may seem to overlap, yet not entirely, for one can have peace but no joy, or even joy without real peace, such as in riding a fast thoroughbred may bring joy, but not be particularly peaceful at all.