Recently, I asked veterans to reflect on what they had learned in their time in uniform and what advice they would give their premilitary selves if they could.

Though the woman and men who responded served at different times and at different places, their reflections contained some common threads. There was a lot of pride expressed in having been challenged and rising — at times reluctantly — to meet that challenge. Appreciation for the nation was another common theme. But the most common thread of all was faith.

Not all military people may believe in an Almighty, but most believe in their fellow service people. The military has undergone lots of changes since Valley Forge, but even back then, some guy buddied up with another guy.

"I made...