Which is better for fitness?

Is it better to take a rest day if your muscles are feeling a little tired and sore from a previous workout, or to do a workout but lift a little lighter and go with a little less intensity? My partner and I are currently doing the booty and flex combo, which we are loving so far, but it’s intense! I’ve done both of these options—taking a rest day and pushing through but lifting a little lighter—but I am interested in what people think about what is best for overall fitness.