When our children were growing up we wanted them to follow our command. Not because we wanted them to be slaves, but because we wanted them to be protected and grow up to be adults. If we used the command for them to stop, it might be what saves their life by not running out into the street and get hit by a car. If we said, don't touch that, we may not want them to get hurt. As Paul writes to the Philippians, he uses several commands like the one in this passage. He tells them and us, to work out our salvation. We often look at this passage with a critical eye. How can we be saved by faith without works, as Paul mentions in Ephesians 2:8,9, if he now tells us to work out our salvation? Participation in the Gospel goes beyond the initial point of faith into a life that is devoted to that faith. So we need to realize that this command is for our good.