Churches are like Power Cords

The analogy, like any other, isn't perfect so don't automatically prescribe this to all situations or anything like that.
Take, for example, a cell phone charger. When you get a new phone the instructions in the manual say that you need to use the phone until the battery is completely empty so that when you finally get to that point that the charger and phone can start their relationship. The phone will probably never again get to that point of no return. Once the phone starts using the charger it will require it for the rest of its life. The cord is critical in the fact that in the case that it is lost, the phone has hours to live.
The optimum life cycle of a phone is, again following the instructions in the manual, to use the phone enough so that you consistently bring it to a lower charge so that it will never get used to getting a small charge. The phone can get a small charge once in a while, but frequent charging it will render it dependent on the cord.

Consider that, for example, the Church is like the power cord. A true Christian would believe that the Church is crucial to the Christian's life, and yet relying on it will render the Christian stale and will, like the cell phone, cut its effective usage life. The best way to live is like MLK said, the church is like the locker room and the game is the rest of the week; go out and spend your charge effectively. However, one does not need to go as far as almost going without it, for leaving the cord with the intent of using up the charge to its great effectiveness instead of wasting it up is what he is talking about.