A: Have you invited John to join the Students’ Union?

B: Sure. He’s a nice guy, always ready to go the extra mile for his friends.

Note: This idiom means to “go above and beyond whatever is required for the task at hand” or to “try harder to please someone.” It’s from the Bible. A law gave a Roman soldier on the march the right to grab any passing Jewish citizen and demand that he carry his kit for a mile. Jesus wanted his followers not just to put up with this but to go farther voluntarily, in a spirit of charity and helpfulness.