If the church wants to be blameless and pure, Paul gives us simple instructions to get there:
We must do everything without arguing, grumbling, or complaining.
He taps into Old Testament history by reminding us how the Israelites acted towards God after being freed from slavery. Even though they had been unshackled from one of the most powerful empires the world has ever known, in a miraculous way, they failed to remember what God did when things got uncomfortable.
Like them, Jesus has set us free from the power of sin and death. If we can see that, first and foremost, our complaining and grumbling will dissolve, and we will shine like stars.