Our identification as a "corporate" church is not a building; rather, it is a relationship of community, where we are His priests!
Peter takes the argument of what our Lord has done for us to show how we are to be as a corporate collaboration of people in Him.
Do not grumble, as in do not be complaining. Don't criticize, find fault, be irritable or argumentative, or whine to fellow believers-and definitely not to unbelievers.
Standing firm, which we can do all the way from sowing the right seed to receiving the greatest harvest of the highest quality.