People in chronic pain must do their activities differently than when they weren't in pain. If they do, they will find that they can eventually be more active and have less pain. External cueing of uptime and downtime activities is important. Using a timer, for example, is helpful in the beginning.
A good example is a person with back pain who determines that standing increases pain after 15 minutes and sitting brings it back to baseline. They then rearrange their daily activities to alternate standing for 15 minutes with sitting for 20 minutes.