Why don't believers need to enjoy the world's goods?
Believers do not need to enjoy the world's goods because their joy is spiritual, not material. Happiness depends on material surroundings, but joy is an attribute of eternal life. Even when circumstances are unhappy, they possess an unspeakable joy that material goods cannot provide or affect.
Les teaches that believers already have eternal life within them (s135). That reality enabled martyrs to face death without fear, because though the flesh can be destroyed, eternal life cannot be touched (s136-s154). Paul admonishes us that by the work of the cross we are justified and also have eternal life (s155-s159). The world is bent on happiness, but happiness is the result of material surroundings, while joy is a spiritual attribute (s164-s170). Paul rarely says "happy" but repeatedly says "rejoice," which comes from the root word joy (s171-s178). When we have eternal life, regardless of whether we are happy or not, we have unspeakable joy (s179-s181). Therefore believers do not necessarily have to enjoy a lot of the world's goods (s182-s183).