A helmet works by a physic’s principle called distributing a force. The hit is spread out over the plastic shell so that it doesn’t affect one place of the cranium directly.
Pushing a thumb tack in is the opposite. This is called concentrating a force. Your finger applies pressure over a wide surface that is concentrated into the pin and even more into the tip. So it slides into the corkboard and not your finger.
When we all come together to pray, it is concentrating a force. When we rally behind a needy brother, we distributing a blow. Some think there’s no longer any need for the church. They are missing out on the power of unity.